<!DOCTYPE HTML>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>intrinsics - </title>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<meta name="description" content="">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="theme-color" content="#ffffff" />
<base href="../">
<link rel="stylesheet" href="book.css">
<link href="https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800" rel="stylesheet" type="text/css">
<link href="https://fonts.googleapis.com/css?family=Source+Code+Pro:500" rel="stylesheet" type="text/css">
<link rel="shortcut icon" href="favicon.png">
<!-- Font Awesome -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css">
<link rel="stylesheet" href="highlight.css">
<link rel="stylesheet" href="tomorrow-night.css">
<link rel="stylesheet" href="ayu-highlight.css">
<!-- Custom theme -->
<!-- Fetch Clipboard.js from CDN but have a local fallback -->
<script src="https://cdn.jsdelivr.net/clipboard.js/1.6.1/clipboard.min.js"></script>
<script>
if (typeof Clipboard == 'undefined') {
document.write(unescape("%3Cscript src='clipboard.min.js'%3E%3C/script%3E"));
}
</script>
</head>
<body class="light">
<!-- Work around some values being stored in localStorage wrapped in quotes -->
<script type="text/javascript">
try {
var theme = localStorage.getItem('mdbook-theme');
var sidebar = localStorage.getItem('mdbook-sidebar');
if (theme.startsWith('"') && theme.endsWith('"')) {
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
}
if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
}
} catch (e) { }
</script>
<!-- Set the theme before any content is loaded, prevents flash -->
<script type="text/javascript">
var theme;
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
if (theme === null || theme === undefined) { theme = 'light'; }
document.body.className = theme;
document.querySelector('html').className = theme;
</script>
<!-- Hide / unhide sidebar before it is displayed -->
<script type="text/javascript">
var sidebar = 'hidden';
if (document.body.clientWidth >= 1080) {
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
sidebar = sidebar || 'visible';
}
document.querySelector('html').classList.add("sidebar-" + sidebar);
</script>
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
<ol class="chapter"><li class="affix"><a href="the-unstable-book.html">The Unstable Book</a></li><li><a href="compiler-flags.html"><strong aria-hidden="true">1.</strong> Compiler flags</a></li><li><ol class="section"><li><a href="compiler-flags/linker-flavor.html"><strong aria-hidden="true">1.1.</strong> linker_flavor</a></li><li><a href="compiler-flags/profile.html"><strong aria-hidden="true">1.2.</strong> profile</a></li><li><a href="compiler-flags/remap-path-prefix.html"><strong aria-hidden="true">1.3.</strong> remap_path_prefix</a></li></ol></li><li><a href="language-features.html"><strong aria-hidden="true">2.</strong> Language features</a></li><li><ol class="section"><li><a href="language-features/abi-msp430-interrupt.html"><strong aria-hidden="true">2.1.</strong> abi_msp430_interrupt</a></li><li><a href="language-features/abi-ptx.html"><strong aria-hidden="true">2.2.</strong> abi_ptx</a></li><li><a href="language-features/abi-thiscall.html"><strong aria-hidden="true">2.3.</strong> abi_thiscall</a></li><li><a href="language-features/abi-unadjusted.html"><strong aria-hidden="true">2.4.</strong> abi_unadjusted</a></li><li><a href="language-features/abi-vectorcall.html"><strong aria-hidden="true">2.5.</strong> abi_vectorcall</a></li><li><a href="language-features/abi-x86-interrupt.html"><strong aria-hidden="true">2.6.</strong> abi_x86_interrupt</a></li><li><a href="language-features/advanced-slice-patterns.html"><strong aria-hidden="true">2.7.</strong> advanced_slice_patterns</a></li><li><a href="language-features/allocator-internals.html"><strong aria-hidden="true">2.8.</strong> allocator_internals</a></li><li><a href="language-features/allow-fail.html"><strong aria-hidden="true">2.9.</strong> allow_fail</a></li><li><a href="language-features/allow-internal-unsafe.html"><strong aria-hidden="true">2.10.</strong> allow_internal_unsafe</a></li><li><a href="language-features/allow-internal-unstable.html"><strong aria-hidden="true">2.11.</strong> allow_internal_unstable</a></li><li><a href="language-features/arbitrary-self-types.html"><strong aria-hidden="true">2.12.</strong> arbitrary_self_types</a></li><li><a href="language-features/asm.html"><strong aria-hidden="true">2.13.</strong> asm</a></li><li><a href="language-features/associated-type-defaults.html"><strong aria-hidden="true">2.14.</strong> associated_type_defaults</a></li><li><a href="language-features/attr-literals.html"><strong aria-hidden="true">2.15.</strong> attr_literals</a></li><li><a href="language-features/box-patterns.html"><strong aria-hidden="true">2.16.</strong> box_patterns</a></li><li><a href="language-features/box-syntax.html"><strong aria-hidden="true">2.17.</strong> box_syntax</a></li><li><a href="language-features/catch-expr.html"><strong aria-hidden="true">2.18.</strong> catch_expr</a></li><li><a href="language-features/cfg-target-feature.html"><strong aria-hidden="true">2.19.</strong> cfg_target_feature</a></li><li><a href="language-features/cfg-target-has-atomic.html"><strong aria-hidden="true">2.20.</strong> cfg_target_has_atomic</a></li><li><a href="language-features/cfg-target-thread-local.html"><strong aria-hidden="true">2.21.</strong> cfg_target_thread_local</a></li><li><a href="language-features/cfg-target-vendor.html"><strong aria-hidden="true">2.22.</strong> cfg_target_vendor</a></li><li><a href="language-features/clone-closures.html"><strong aria-hidden="true">2.23.</strong> clone_closures</a></li><li><a href="language-features/compiler-builtins.html"><strong aria-hidden="true">2.24.</strong> compiler_builtins</a></li><li><a href="language-features/concat-idents.html"><strong aria-hidden="true">2.25.</strong> concat_idents</a></li><li><a href="language-features/conservative-impl-trait.html"><strong aria-hidden="true">2.26.</strong> conservative_impl_trait</a></li><li><a href="language-features/const-fn.html"><strong aria-hidden="true">2.27.</strong> const_fn</a></li><li><a href="language-features/const-indexing.html"><strong aria-hidden="true">2.28.</strong> const_indexing</a></li><li><a href="language-features/copy-closures.html"><strong aria-hidden="true">2.29.</strong> copy_closures</a></li><li><a href="language-features/crate-in-paths.html"><strong aria-hidden="true">2.30.</strong> crate_in_paths</a></li><li><a href="language-features/crate-visibility-modifier.html"><strong aria-hidden="true">2.31.</strong> crate_visibility_modifier</a></li><li><a href="language-features/custom-attribute.html"><strong aria-hidden="true">2.32.</strong> custom_attribute</a></li><li><a href="language-features/custom-derive.html"><strong aria-hidden="true">2.33.</strong> custom_derive</a></li><li><a href="language-features/decl-macro.html"><strong aria-hidden="true">2.34.</strong> decl_macro</a></li><li><a href="language-features/default-type-parameter-fallback.html"><strong aria-hidden="true">2.35.</strong> default_type_parameter_fallback</a></li><li><a href="language-features/doc-cfg.html"><strong aria-hidden="true">2.36.</strong> doc_cfg</a></li><li><a href="language-features/doc-masked.html"><strong aria-hidden="true">2.37.</strong> doc_masked</a></li><li><a href="language-features/doc-spotlight.html"><strong aria-hidden="true">2.38.</strong> doc_spotlight</a></li><li><a href="language-features/dotdoteq-in-patterns.html"><strong aria-hidden="true">2.39.</strong> dotdoteq_in_patterns</a></li><li><a href="language-features/dropck-eyepatch.html"><strong aria-hidden="true">2.40.</strong> dropck_eyepatch</a></li><li><a href="language-features/dropck-parametricity.html"><strong aria-hidden="true">2.41.</strong> dropck_parametricity</a></li><li><a href="language-features/dyn-trait.html"><strong aria-hidden="true">2.42.</strong> dyn_trait</a></li><li><a href="language-features/exclusive-range-pattern.html"><strong aria-hidden="true">2.43.</strong> exclusive_range_pattern</a></li><li><a href="language-features/extern-absolute-paths.html"><strong aria-hidden="true">2.44.</strong> extern_absolute_paths</a></li><li><a href="language-features/extern-in-paths.html"><strong aria-hidden="true">2.45.</strong> extern_in_paths</a></li><li><a href="language-features/extern-types.html"><strong aria-hidden="true">2.46.</strong> extern_types</a></li><li><a href="language-features/external-doc.html"><strong aria-hidden="true">2.47.</strong> external_doc</a></li><li><a href="language-features/fn-must-use.html"><strong aria-hidden="true">2.48.</strong> fn_must_use</a></li><li><a href="language-features/fundamental.html"><strong aria-hidden="true">2.49.</strong> fundamental</a></li><li><a href="language-features/generators.html"><strong aria-hidden="true">2.50.</strong> generators</a></li><li><a href="language-features/generic-associated-types.html"><strong aria-hidden="true">2.51.</strong> generic_associated_types</a></li><li><a href="language-features/generic-param-attrs.html"><strong aria-hidden="true">2.52.</strong> generic_param_attrs</a></li><li><a href="language-features/global-allocator.html"><strong aria-hidden="true">2.53.</strong> global_allocator</a></li><li><a href="language-features/global-asm.html"><strong aria-hidden="true">2.54.</strong> global_asm</a></li><li><a href="language-features/i128-type.html"><strong aria-hidden="true">2.55.</strong> i128_type</a></li><li><a href="language-features/in-band-lifetimes.html"><strong aria-hidden="true">2.56.</strong> in_band_lifetimes</a></li><li><a href="language-features/inclusive-range-syntax.html"><strong aria-hidden="true">2.57.</strong> inclusive_range_syntax</a></li><li><a href="language-features/intrinsics.html" class="active"><strong aria-hidden="true">2.58.</strong> intrinsics</a></li><li><a href="language-features/lang-items.html"><strong aria-hidden="true">2.59.</strong> lang_items</a></li><li><a href="language-features/link-args.html"><strong aria-hidden="true">2.60.</strong> link_args</a></li><li><a href="language-features/link-cfg.html"><strong aria-hidden="true">2.61.</strong> link_cfg</a></li><li><a href="language-features/link-llvm-intrinsics.html"><strong aria-hidden="true">2.62.</strong> link_llvm_intrinsics</a></li><li><a href="language-features/linkage.html"><strong aria-hidden="true">2.63.</strong> linkage</a></li><li><a href="language-features/log-syntax.html"><strong aria-hidden="true">2.64.</strong> log_syntax</a></li><li><a href="language-features/macro-at-most-once-rep.html"><strong aria-hidden="true">2.65.</strong> macro_at_most_once_rep</a></li><li><a href="language-features/macro-lifetime-matcher.html"><strong aria-hidden="true">2.66.</strong> macro_lifetime_matcher</a></li><li><a href="language-features/macro-reexport.html"><strong aria-hidden="true">2.67.</strong> macro_reexport</a></li><li><a href="language-features/macro-vis-matcher.html"><strong aria-hidden="true">2.68.</strong> macro_vis_matcher</a></li><li><a href="language-features/main.html"><strong aria-hidden="true">2.69.</strong> main</a></li><li><a href="language-features/match-default-bindings.html"><strong aria-hidden="true">2.70.</strong> match_default_bindings</a></li><li><a href="language-features/naked-functions.html"><strong aria-hidden="true">2.71.</strong> naked_functions</a></li><li><a href="language-features/needs-allocator.html"><strong aria-hidden="true">2.72.</strong> needs_allocator</a></li><li><a href="language-features/needs-panic-runtime.html"><strong aria-hidden="true">2.73.</strong> needs_panic_runtime</a></li><li><a href="language-features/nested-impl-trait.html"><strong aria-hidden="true">2.74.</strong> nested_impl_trait</a></li><li><a href="language-features/never-type.html"><strong aria-hidden="true">2.75.</strong> never_type</a></li><li><a href="language-features/nll.html"><strong aria-hidden="true">2.76.</strong> nll</a></li><li><a href="language-features/no-core.html"><strong aria-hidden="true">2.77.</strong> no_core</a></li><li><a href="language-features/no-debug.html"><strong aria-hidden="true">2.78.</strong> no_debug</a></li><li><a href="language-features/non-ascii-idents.html"><strong aria-hidden="true">2.79.</strong> non_ascii_idents</a></li><li><a href="language-features/non-exhaustive.html"><strong aria-hidden="true">2.80.</strong> non_exhaustive</a></li><li><a href="language-features/non-modrs-mods.html"><strong aria-hidden="true">2.81.</strong> non_modrs_mods</a></li><li><a href="language-features/omit-gdb-pretty-printer-section.html"><strong aria-hidden="true">2.82.</strong> omit_gdb_pretty_printer_section</a></li><li><a href="language-features/on-unimplemented.html"><strong aria-hidden="true">2.83.</strong> on_unimplemented</a></li><li><a href="language-features/optin-builtin-traits.html"><strong aria-hidden="true">2.84.</strong> optin_builtin_traits</a></li><li><a href="language-features/overlapping-marker-traits.html"><strong aria-hidden="true">2.85.</strong> overlapping_marker_traits</a></li><li><a href="language-features/panic-runtime.html"><strong aria-hidden="true">2.86.</strong> panic_runtime</a></li><li><a href="language-features/placement-in-syntax.html"><strong aria-hidden="true">2.87.</strong> placement_in_syntax</a></li><li><a href="language-features/platform-intrinsics.html"><strong aria-hidden="true">2.88.</strong> platform_intrinsics</a></li><li><a href="language-features/plugin.html"><strong aria-hidden="true">2.89.</strong> plugin</a></li><li><a href="language-features/plugin-registrar.html"><strong aria-hidden="true">2.90.</strong> plugin_registrar</a></li><li><a href="language-features/prelude-import.html"><strong aria-hidden="true">2.91.</strong> prelude_import</a></li><li><a href="language-features/proc-macro.html"><strong aria-hidden="true">2.92.</strong> proc_macro</a></li><li><a href="language-features/profiler-runtime.html"><strong aria-hidden="true">2.93.</strong> profiler_runtime</a></li><li><a href="language-features/quote.html"><strong aria-hidden="true">2.94.</strong> quote</a></li><li><a href="language-features/repr-simd.html"><strong aria-hidden="true">2.95.</strong> repr_simd</a></li><li><a href="language-features/repr-transparent.html"><strong aria-hidden="true">2.96.</strong> repr_transparent</a></li><li><a href="language-features/repr128.html"><strong aria-hidden="true">2.97.</strong> repr128</a></li><li><a href="language-features/rustc-attrs.html"><strong aria-hidden="true">2.98.</strong> rustc_attrs</a></li><li><a href="language-features/rustc-const-unstable.html"><strong aria-hidden="true">2.99.</strong> rustc_const_unstable</a></li><li><a href="language-features/rustc-diagnostic-macros.html"><strong aria-hidden="true">2.100.</strong> rustc_diagnostic_macros</a></li><li><a href="language-features/sanitizer-runtime.html"><strong aria-hidden="true">2.101.</strong> sanitizer_runtime</a></li><li><a href="language-features/simd-ffi.html"><strong aria-hidden="true">2.102.</strong> simd_ffi</a></li><li><a href="language-features/slice-patterns.html"><strong aria-hidden="true">2.103.</strong> slice_patterns</a></li><li><a href="language-features/specialization.html"><strong aria-hidden="true">2.104.</strong> specialization</a></li><li><a href="language-features/staged-api.html"><strong aria-hidden="true">2.105.</strong> staged_api</a></li><li><a href="language-features/start.html"><strong aria-hidden="true">2.106.</strong> start</a></li><li><a href="language-features/static-nobundle.html"><strong aria-hidden="true">2.107.</strong> static_nobundle</a></li><li><a href="language-features/stmt-expr-attributes.html"><strong aria-hidden="true">2.108.</strong> stmt_expr_attributes</a></li><li><a href="language-features/structural-match.html"><strong aria-hidden="true">2.109.</strong> structural_match</a></li><li><a href="language-features/target-feature.html"><strong aria-hidden="true">2.110.</strong> target_feature</a></li><li><a href="language-features/termination-trait.html"><strong aria-hidden="true">2.111.</strong> termination_trait</a></li><li><a href="language-features/thread-local.html"><strong aria-hidden="true">2.112.</strong> thread_local</a></li><li><a href="language-features/trace-macros.html"><strong aria-hidden="true">2.113.</strong> trace_macros</a></li><li><a href="language-features/trait-alias.html"><strong aria-hidden="true">2.114.</strong> trait_alias</a></li><li><a href="language-features/type-ascription.html"><strong aria-hidden="true">2.115.</strong> type_ascription</a></li><li><a href="language-features/unboxed-closures.html"><strong aria-hidden="true">2.116.</strong> unboxed_closures</a></li><li><a href="language-features/underscore-lifetimes.html"><strong aria-hidden="true">2.117.</strong> underscore_lifetimes</a></li><li><a href="language-features/universal-impl-trait.html"><strong aria-hidden="true">2.118.</strong> universal_impl_trait</a></li><li><a href="language-features/unsized-tuple-coercion.html"><strong aria-hidden="true">2.119.</strong> unsized_tuple_coercion</a></li><li><a href="language-features/untagged-unions.html"><strong aria-hidden="true">2.120.</strong> untagged_unions</a></li><li><a href="language-features/unwind-attributes.html"><strong aria-hidden="true">2.121.</strong> unwind_attributes</a></li><li><a href="language-features/use-extern-macros.html"><strong aria-hidden="true">2.122.</strong> use_extern_macros</a></li><li><a href="language-features/used.html"><strong aria-hidden="true">2.123.</strong> used</a></li><li><a href="language-features/wasm-import-memory.html"><strong aria-hidden="true">2.124.</strong> wasm_import_memory</a></li></ol></li><li><a href="library-features.html"><strong aria-hidden="true">3.</strong> Library Features</a></li><li><ol class="section"><li><a href="library-features/align-offset.html"><strong aria-hidden="true">3.1.</strong> align_offset</a></li><li><a href="library-features/alloc.html"><strong aria-hidden="true">3.2.</strong> alloc</a></li><li><a href="library-features/alloc-jemalloc.html"><strong aria-hidden="true">3.3.</strong> alloc_jemalloc</a></li><li><a href="library-features/alloc-system.html"><strong aria-hidden="true">3.4.</strong> alloc_system</a></li><li><a href="library-features/allocator-api.html"><strong aria-hidden="true">3.5.</strong> allocator_api</a></li><li><a href="library-features/array-error-internals.html"><strong aria-hidden="true">3.6.</strong> array_error_internals</a></li><li><a href="library-features/ascii-ctype.html"><strong aria-hidden="true">3.7.</strong> ascii_ctype</a></li><li><a href="library-features/box-heap.html"><strong aria-hidden="true">3.8.</strong> box_heap</a></li><li><a href="library-features/box-into-raw-non-null.html"><strong aria-hidden="true">3.9.</strong> box_into_raw_non_null</a></li><li><a href="library-features/box-leak.html"><strong aria-hidden="true">3.10.</strong> box_leak</a></li><li><a href="library-features/bufreader-is-empty.html"><strong aria-hidden="true">3.11.</strong> bufreader_is_empty</a></li><li><a href="library-features/bufreader-seek-relative.html"><strong aria-hidden="true">3.12.</strong> bufreader_seek_relative</a></li><li><a href="library-features/c-void-variant.html"><strong aria-hidden="true">3.13.</strong> c_void_variant</a></li><li><a href="library-features/char-error-internals.html"><strong aria-hidden="true">3.14.</strong> char_error_internals</a></li><li><a href="library-features/coerce-unsized.html"><strong aria-hidden="true">3.15.</strong> coerce_unsized</a></li><li><a href="library-features/collection-placement.html"><strong aria-hidden="true">3.16.</strong> collection_placement</a></li><li><a href="library-features/collections-range.html"><strong aria-hidden="true">3.17.</strong> collections_range</a></li><li><a href="library-features/compiler-builtins-lib.html"><strong aria-hidden="true">3.18.</strong> compiler_builtins_lib</a></li><li><a href="library-features/concat-idents-macro.html"><strong aria-hidden="true">3.19.</strong> concat_idents_macro</a></li><li><a href="library-features/const-type-id.html"><strong aria-hidden="true">3.20.</strong> const_type_id</a></li><li><a href="library-features/core-char-ext.html"><strong aria-hidden="true">3.21.</strong> core_char_ext</a></li><li><a href="library-features/core-float.html"><strong aria-hidden="true">3.22.</strong> core_float</a></li><li><a href="library-features/core-intrinsics.html"><strong aria-hidden="true">3.23.</strong> core_intrinsics</a></li><li><a href="library-features/core-panic.html"><strong aria-hidden="true">3.24.</strong> core_panic</a></li><li><a href="library-features/core-private-bignum.html"><strong aria-hidden="true">3.25.</strong> core_private_bignum</a></li><li><a href="library-features/core-private-diy-float.html"><strong aria-hidden="true">3.26.</strong> core_private_diy_float</a></li><li><a href="library-features/core-slice-ext.html"><strong aria-hidden="true">3.27.</strong> core_slice_ext</a></li><li><a href="library-features/core-str-ext.html"><strong aria-hidden="true">3.28.</strong> core_str_ext</a></li><li><a href="library-features/cursor-mut-vec.html"><strong aria-hidden="true">3.29.</strong> cursor_mut_vec</a></li><li><a href="library-features/deadline-api.html"><strong aria-hidden="true">3.30.</strong> deadline_api</a></li><li><a href="library-features/dec2flt.html"><strong aria-hidden="true">3.31.</strong> dec2flt</a></li><li><a href="library-features/decode-utf8.html"><strong aria-hidden="true">3.32.</strong> decode_utf8</a></li><li><a href="library-features/derive-clone-copy.html"><strong aria-hidden="true">3.33.</strong> derive_clone_copy</a></li><li><a href="library-features/derive-eq.html"><strong aria-hidden="true">3.34.</strong> derive_eq</a></li><li><a href="library-features/drain-filter.html"><strong aria-hidden="true">3.35.</strong> drain_filter</a></li><li><a href="library-features/duration-extras.html"><strong aria-hidden="true">3.36.</strong> duration_extras</a></li><li><a href="library-features/duration-from-micros.html"><strong aria-hidden="true">3.37.</strong> duration_from_micros</a></li><li><a href="library-features/entry-and-modify.html"><strong aria-hidden="true">3.38.</strong> entry_and_modify</a></li><li><a href="library-features/entry-or-default.html"><strong aria-hidden="true">3.39.</strong> entry_or_default</a></li><li><a href="library-features/error-type-id.html"><strong aria-hidden="true">3.40.</strong> error_type_id</a></li><li><a href="library-features/exact-chunks.html"><strong aria-hidden="true">3.41.</strong> exact_chunks</a></li><li><a href="library-features/exact-size-is-empty.html"><strong aria-hidden="true">3.42.</strong> exact_size_is_empty</a></li><li><a href="library-features/fd.html"><strong aria-hidden="true">3.43.</strong> fd</a></li><li><a href="library-features/fd-read.html"><strong aria-hidden="true">3.44.</strong> fd_read</a></li><li><a href="library-features/fixed-size-array.html"><strong aria-hidden="true">3.45.</strong> fixed_size_array</a></li><li><a href="library-features/flt2dec.html"><strong aria-hidden="true">3.46.</strong> flt2dec</a></li><li><a href="library-features/fmt-flags-align.html"><strong aria-hidden="true">3.47.</strong> fmt_flags_align</a></li><li><a href="library-features/fmt-internals.html"><strong aria-hidden="true">3.48.</strong> fmt_internals</a></li><li><a href="library-features/fn-traits.html"><strong aria-hidden="true">3.49.</strong> fn_traits</a></li><li><a href="library-features/fnbox.html"><strong aria-hidden="true">3.50.</strong> fnbox</a></li><li><a href="library-features/from-ref.html"><strong aria-hidden="true">3.51.</strong> from_ref</a></li><li><a href="library-features/from-utf8-error-as-bytes.html"><strong aria-hidden="true">3.52.</strong> from_utf8_error_as_bytes</a></li><li><a href="library-features/fs-read-write.html"><strong aria-hidden="true">3.53.</strong> fs_read_write</a></li><li><a href="library-features/fused.html"><strong aria-hidden="true">3.54.</strong> fused</a></li><li><a href="library-features/future-atomic-orderings.html"><strong aria-hidden="true">3.55.</strong> future_atomic_orderings</a></li><li><a href="library-features/generator-trait.html"><strong aria-hidden="true">3.56.</strong> generator_trait</a></li><li><a href="library-features/get-type-id.html"><strong aria-hidden="true">3.57.</strong> get_type_id</a></li><li><a href="library-features/getpid.html"><strong aria-hidden="true">3.58.</strong> getpid</a></li><li><a href="library-features/hash-map-remove-entry.html"><strong aria-hidden="true">3.59.</strong> hash_map_remove_entry</a></li><li><a href="library-features/heap-api.html"><strong aria-hidden="true">3.60.</strong> heap_api</a></li><li><a href="library-features/i128.html"><strong aria-hidden="true">3.61.</strong> i128</a></li><li><a href="library-features/inclusive-range.html"><strong aria-hidden="true">3.62.</strong> inclusive_range</a></li><li><a href="library-features/int-error-internals.html"><strong aria-hidden="true">3.63.</strong> int_error_internals</a></li><li><a href="library-features/integer-atomics.html"><strong aria-hidden="true">3.64.</strong> integer_atomics</a></li><li><a href="library-features/io.html"><strong aria-hidden="true">3.65.</strong> io</a></li><li><a href="library-features/io-error-internals.html"><strong aria-hidden="true">3.66.</strong> io_error_internals</a></li><li><a href="library-features/ip.html"><strong aria-hidden="true">3.67.</strong> ip</a></li><li><a href="library-features/ip-constructors.html"><strong aria-hidden="true">3.68.</strong> ip_constructors</a></li><li><a href="library-features/iter-rfind.html"><strong aria-hidden="true">3.69.</strong> iter_rfind</a></li><li><a href="library-features/iter-rfold.html"><strong aria-hidden="true">3.70.</strong> iter_rfold</a></li><li><a href="library-features/iterator-step-by.html"><strong aria-hidden="true">3.71.</strong> iterator_step_by</a></li><li><a href="library-features/iterator-try-fold.html"><strong aria-hidden="true">3.72.</strong> iterator_try_fold</a></li><li><a href="library-features/libstd-io-internals.html"><strong aria-hidden="true">3.73.</strong> libstd_io_internals</a></li><li><a href="library-features/libstd-sys-internals.html"><strong aria-hidden="true">3.74.</strong> libstd_sys_internals</a></li><li><a href="library-features/libstd-thread-internals.html"><strong aria-hidden="true">3.75.</strong> libstd_thread_internals</a></li><li><a href="library-features/linked-list-extras.html"><strong aria-hidden="true">3.76.</strong> linked_list_extras</a></li><li><a href="library-features/lookup-host.html"><strong aria-hidden="true">3.77.</strong> lookup_host</a></li><li><a href="library-features/map-entry-replace.html"><strong aria-hidden="true">3.78.</strong> map_entry_replace</a></li><li><a href="library-features/mpsc-select.html"><strong aria-hidden="true">3.79.</strong> mpsc_select</a></li><li><a href="library-features/n16.html"><strong aria-hidden="true">3.80.</strong> n16</a></li><li><a href="library-features/nonnull-cast.html"><strong aria-hidden="true">3.81.</strong> nonnull_cast</a></li><li><a href="library-features/nonzero.html"><strong aria-hidden="true">3.82.</strong> nonzero</a></li><li><a href="library-features/offset-to.html"><strong aria-hidden="true">3.83.</strong> offset_to</a></li><li><a href="library-features/once-poison.html"><strong aria-hidden="true">3.84.</strong> once_poison</a></li><li><a href="library-features/option-filter.html"><strong aria-hidden="true">3.85.</strong> option_filter</a></li><li><a href="library-features/option-ref-mut-cloned.html"><strong aria-hidden="true">3.86.</strong> option_ref_mut_cloned</a></li><li><a href="library-features/panic-abort.html"><strong aria-hidden="true">3.87.</strong> panic_abort</a></li><li><a href="library-features/panic-unwind.html"><strong aria-hidden="true">3.88.</strong> panic_unwind</a></li><li><a href="library-features/pattern.html"><strong aria-hidden="true">3.89.</strong> pattern</a></li><li><a href="library-features/placement-in.html"><strong aria-hidden="true">3.90.</strong> placement_in</a></li><li><a href="library-features/placement-new-protocol.html"><strong aria-hidden="true">3.91.</strong> placement_new_protocol</a></li><li><a href="library-features/pointer-methods.html"><strong aria-hidden="true">3.92.</strong> pointer_methods</a></li><li><a href="library-features/print-internals.html"><strong aria-hidden="true">3.93.</strong> print_internals</a></li><li><a href="library-features/proc-macro-internals.html"><strong aria-hidden="true">3.94.</strong> proc_macro_internals</a></li><li><a href="library-features/process-internals.html"><strong aria-hidden="true">3.95.</strong> process_internals</a></li><li><a href="library-features/profiler-runtime-lib.html"><strong aria-hidden="true">3.96.</strong> profiler_runtime_lib</a></li><li><a href="library-features/ptr-internals.html"><strong aria-hidden="true">3.97.</strong> ptr_internals</a></li><li><a href="library-features/range-contains.html"><strong aria-hidden="true">3.98.</strong> range_contains</a></li><li><a href="library-features/raw.html"><strong aria-hidden="true">3.99.</strong> raw</a></li><li><a href="library-features/rc-downcast.html"><strong aria-hidden="true">3.100.</strong> rc_downcast</a></li><li><a href="library-features/read-initializer.html"><strong aria-hidden="true">3.101.</strong> read_initializer</a></li><li><a href="library-features/refcell-replace-swap.html"><strong aria-hidden="true">3.102.</strong> refcell_replace_swap</a></li><li><a href="library-features/rt.html"><strong aria-hidden="true">3.103.</strong> rt</a></li><li><a href="library-features/rustc-private.html"><strong aria-hidden="true">3.104.</strong> rustc_private</a></li><li><a href="library-features/sanitizer-runtime-lib.html"><strong aria-hidden="true">3.105.</strong> sanitizer_runtime_lib</a></li><li><a href="library-features/set-stdio.html"><strong aria-hidden="true">3.106.</strong> set_stdio</a></li><li><a href="library-features/shared.html"><strong aria-hidden="true">3.107.</strong> shared</a></li><li><a href="library-features/sip-hash-13.html"><strong aria-hidden="true">3.108.</strong> sip_hash_13</a></li><li><a href="library-features/slice-concat-ext.html"><strong aria-hidden="true">3.109.</strong> slice_concat_ext</a></li><li><a href="library-features/slice-get-slice.html"><strong aria-hidden="true">3.110.</strong> slice_get_slice</a></li><li><a href="library-features/slice-internals.html"><strong aria-hidden="true">3.111.</strong> slice_internals</a></li><li><a href="library-features/slice-rotate.html"><strong aria-hidden="true">3.112.</strong> slice_rotate</a></li><li><a href="library-features/slice-rsplit.html"><strong aria-hidden="true">3.113.</strong> slice_rsplit</a></li><li><a href="library-features/sort-internals.html"><strong aria-hidden="true">3.114.</strong> sort_internals</a></li><li><a href="library-features/splice.html"><strong aria-hidden="true">3.115.</strong> splice</a></li><li><a href="library-features/std-internals.html"><strong aria-hidden="true">3.116.</strong> std_internals</a></li><li><a href="library-features/step-trait.html"><strong aria-hidden="true">3.117.</strong> step_trait</a></li><li><a href="library-features/str-escape.html"><strong aria-hidden="true">3.118.</strong> str_escape</a></li><li><a href="library-features/str-internals.html"><strong aria-hidden="true">3.119.</strong> str_internals</a></li><li><a href="library-features/string-retain.html"><strong aria-hidden="true">3.120.</strong> string_retain</a></li><li><a href="library-features/swap-nonoverlapping.html"><strong aria-hidden="true">3.121.</strong> swap_nonoverlapping</a></li><li><a href="library-features/swap-with-slice.html"><strong aria-hidden="true">3.122.</strong> swap_with_slice</a></li><li><a href="library-features/take-set-limit.html"><strong aria-hidden="true">3.123.</strong> take_set_limit</a></li><li><a href="library-features/test.html"><strong aria-hidden="true">3.124.</strong> test</a></li><li><a href="library-features/thread-local-internals.html"><strong aria-hidden="true">3.125.</strong> thread_local_internals</a></li><li><a href="library-features/thread-local-state.html"><strong aria-hidden="true">3.126.</strong> thread_local_state</a></li><li><a href="library-features/toowned-clone-into.html"><strong aria-hidden="true">3.127.</strong> toowned_clone_into</a></li><li><a href="library-features/transpose-result.html"><strong aria-hidden="true">3.128.</strong> transpose_result</a></li><li><a href="library-features/trusted-len.html"><strong aria-hidden="true">3.129.</strong> trusted_len</a></li><li><a href="library-features/try-from.html"><strong aria-hidden="true">3.130.</strong> try_from</a></li><li><a href="library-features/try-trait.html"><strong aria-hidden="true">3.131.</strong> try_trait</a></li><li><a href="library-features/unicode.html"><strong aria-hidden="true">3.132.</strong> unicode</a></li><li><a href="library-features/unix-ppid.html"><strong aria-hidden="true">3.133.</strong> unix_ppid</a></li><li><a href="library-features/unreachable.html"><strong aria-hidden="true">3.134.</strong> unreachable</a></li><li><a href="library-features/unsize.html"><strong aria-hidden="true">3.135.</strong> unsize</a></li><li><a href="library-features/update-panic-count.html"><strong aria-hidden="true">3.136.</strong> update_panic_count</a></li><li><a href="library-features/vec-remove-item.html"><strong aria-hidden="true">3.137.</strong> vec_remove_item</a></li><li><a href="library-features/vec-resize-default.html"><strong aria-hidden="true">3.138.</strong> vec_resize_default</a></li><li><a href="library-features/windows-c.html"><strong aria-hidden="true">3.139.</strong> windows_c</a></li><li><a href="library-features/windows-handle.html"><strong aria-hidden="true">3.140.</strong> windows_handle</a></li><li><a href="library-features/windows-net.html"><strong aria-hidden="true">3.141.</strong> windows_net</a></li><li><a href="library-features/windows-stdio.html"><strong aria-hidden="true">3.142.</strong> windows_stdio</a></li></ol></li></ol>
</nav>
<div id="page-wrapper" class="page-wrapper">
<div class="page">
<div id="menu-bar" class="menu-bar">
<div id="menu-bar-sticky-container">
<div class="left-buttons">
<button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
<i class="fa fa-bars"></i>
</button>
<button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
<i class="fa fa-paint-brush"></i>
</button>
<ul id="theme-list" class="theme-popup" aria-label="submenu">
<li><button class="theme" id="light">Light <span class="default">(default)</span></button></li>
<li><button class="theme" id="rust">Rust</button></li>
<li><button class="theme" id="coal">Coal</button></li>
<li><button class="theme" id="navy">Navy</button></li>
<li><button class="theme" id="ayu">Ayu</button></li>
</ul>
</div>
<h1 class="menu-title"></h1>
<div class="right-buttons">
<a href="print.html" title="Print this book" aria-label="Print this book">
<i id="print-button" class="fa fa-print"></i>
</a>
</div>
</div>
</div>
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
<script type="text/javascript">
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
});
</script>
<div id="content" class="content">
<main>
<a class="header" href="language-features/intrinsics.html#intrinsics" id="intrinsics"><h1><code>intrinsics</code></h1></a>
<p>The tracking issue for this feature is: None.</p>
<p>Intrinsics are never intended to be stable directly, but intrinsics are often
exported in some sort of stable manner. Prefer using the stable interfaces to
the intrinsic directly when you can.</p>
<hr />
<p>These are imported as if they were FFI functions, with the special
<code>rust-intrinsic</code> ABI. For example, if one was in a freestanding
context, but wished to be able to <code>transmute</code> between types, and
perform efficient pointer arithmetic, one would import those functions
via a declaration like</p>
<pre><pre class="playpen"><code class="language-rust">#![feature(intrinsics)]
# fn main() {}
extern "rust-intrinsic" {
fn transmute<T, U>(x: T) -> U;
fn offset<T>(dst: *const T, offset: isize) -> *const T;
}
</code></pre></pre>
<p>As with any other FFI functions, these are always <code>unsafe</code> to call.</p>
</main>
<nav class="nav-wrapper" aria-label="Page navigation">
<!-- Mobile navigation buttons -->
<a rel="prev" href="language-features/inclusive-range-syntax.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a rel="next" href="language-features/lang-items.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
<div style="clear: both"></div>
</nav>
</div>
</div>
<nav class="nav-wide-wrapper" aria-label="Page navigation">
<a href="language-features/inclusive-range-syntax.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a href="language-features/lang-items.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
</nav>
</div>
<!-- Local fallback for Font Awesome -->
<script>
if (getComputedStyle(document.querySelector(".fa")).fontFamily !== "FontAwesome") {
var link = document.createElement('link');
link.rel = 'stylesheet';
link.type = 'text/css';
link.href = '_FontAwesome/css/font-awesome.css';
document.head.insertBefore(link, document.head.firstChild)
}
</script>
<script src="highlight.js"></script>
<script src="book.js"></script>
<!-- Custom JS script -->
</body>
</html>
distrib
>
Mageia
>
6
>
x86_64
>
media
>
core-updates
>
by-pkgid
>
fdedb3cf2140df9b6d419a2338ab1caa
>
files
>
6378
