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< cpp
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===[[cpp/types|Type support]]===
 
===[[cpp/types|Type support]]===
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Basic types (e.g. {{lc|std::size_t}}, {{lc|std::nullptr_t}}), RTTI (e.g. {{lc|std::type_info}}), type traits (e.g. {{lc|std::is_integral}}, {{lc|std::rank}})
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Basic types (e.g. {{lc|std::size_t}}, {{lc|std::nullptr_t}}), RTTI (e.g. {{lc|std::type_info}})
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===[[cpp/meta|Metaprogramming]]===
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Type traits (e.g. {{lc|std::is_integral}}, {{lc|std::rank}}), compile-time constants (e.g. {{lc|std::integer_sequence}}, {{lc|std::ratio}})
  
 
===Constant evaluation context===
 
===Constant evaluation context===
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{{dsc header|source_location}}
 
{{dsc header|source_location}}
 
{{dsc inc|cpp/utility/dsc source_location}}
 
{{dsc inc|cpp/utility/dsc source_location}}
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{{dsc end}}
 
−
 
−
===Debugging support===
 
−
{{dsc begin}}
 
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{{dsc header|debugging}}
 
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{{dsc inc | cpp/utility/dsc breakpoint}}
 
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{{dsc inc | cpp/utility/dsc breakpoint_if_debugging}}
 
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{{dsc inc | cpp/utility/dsc is_debugger_present}}
 
 
{{dsc end}}
 
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===[[cpp/utility/variadic|Variadic functions]]===
 
===[[cpp/utility/variadic|Variadic functions]]===
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Support for functions that take an arbitrary number of parameters (via e.g. {{lc|va_start}}, {{lc|va_arg}}, {{lc|va_end}})
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Support for functions that take an arbitrary number of parameters (via e.g. {{lc|va_start}}, {{lc|va_arg}}, {{lc|va_end}}).
  
 
==General-purpose utilities==
 
==General-purpose utilities==
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===Swap===
 
===Swap===
 
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{{dsc begin}}
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{{dsc namespace|std::rel_ops}}
 
{{dsc namespace|std::rel_ops}}
 
{{dsc inc|cpp/utility/rel_ops/dsc operator_cmp}}
 
{{dsc inc|cpp/utility/rel_ops/dsc operator_cmp}}
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{{dsc end}}
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===Construction tags===
 +
{{dsc begin}}
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{{dsc header|utility}}
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{{dsc inc|cpp/utility/dsc piecewise_construct}}
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{{dsc header|utility}}
 
{{dsc header|utility}}
 
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{{dsc inc|cpp/utility/dsc integer_sequence}}
 
 
{{dsc header|tuple}}
 
{{dsc header|tuple}}
 
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{{dsc header|array}}
 
{{dsc header|array}}
 
{{dsc header|ranges}}
 
{{dsc header|ranges}}
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{{dsc header|complex}}
 
{{dsc inc|cpp/utility/dsc tuple_size}}
 
{{dsc inc|cpp/utility/dsc tuple_size}}
 
{{dsc inc|cpp/utility/dsc tuple_element}}
 
{{dsc inc|cpp/utility/dsc tuple_element}}
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{{dsc header|any}}
 
{{dsc header|any}}
 
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{{dsc inc|cpp/utility/dsc any}}
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{{dsc sep}}
 
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{{dsc header|utility}}
 
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Time tracking (e.g. {{lc|std::chrono::time_point}}, {{lc|std::chrono::duration}}), C-style date and time (e.g. {{lc|std::time}}, {{lc|std::clock}})
 
Time tracking (e.g. {{lc|std::chrono::time_point}}, {{lc|std::chrono::duration}}), C-style date and time (e.g. {{lc|std::time}}, {{lc|std::clock}})
  
−
===Elementary string conversions===
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===Primitive string conversions===
 
In addition to sophisticated locale-dependent parsers and formatters provided by the [[cpp/io|C++ I/O]] library, the [[cpp/io/c|C I/O]] library, [[cpp/string/basic_string#Numeric conversions|C++ string converters]], and [[cpp/string/byte#Conversions to numeric formats|C string converters]], the header {{header|charconv}} provides light-weight, locale-independent, non-allocating, non-throwing parsers and formatters for arithmetic types.
 
In addition to sophisticated locale-dependent parsers and formatters provided by the [[cpp/io|C++ I/O]] library, the [[cpp/io/c|C I/O]] library, [[cpp/string/basic_string#Numeric conversions|C++ string converters]], and [[cpp/string/byte#Conversions to numeric formats|C string converters]], the header {{header|charconv}} provides light-weight, locale-independent, non-allocating, non-throwing parsers and formatters for arithmetic types.
 
{{dsc begin}}
 
{{dsc begin}}

Latest revision as of 01:42, 14 November 2024

 
C++
 
Utilities library
General utilities
Relational operators (deprecated in C++20)
 

C++ includes a variety of utility libraries that provide functionality ranging from bit-counting to partial function application. These libraries can be broadly divided into two groups:

  • language support libraries, and
  • general-purpose libraries.

Contents

[edit] Language support

Language support libraries provide classes and functions that interact closely with language features and support common language idioms.

[edit] Type support

Basic types (e.g. std::size_t, std::nullptr_t), RTTI (e.g. std::type_info)

[edit] Metaprogramming

Type traits (e.g. std::is_integral, std::rank), compile-time constants (e.g. std::integer_sequence, std::ratio)

[edit] Constant evaluation context

Defined in header <type_traits>
(C++20)
 detects whether the call occurs within a constant-evaluated context
(function) [edit]
(C++26)
 checks whether a pointer is within the object's lifetime at compile time
(function) [edit]

[edit] Implementation properties

The header <version> supplies implementation-dependent information about the C++ standard library (such as the version number and release date). It also defines the library feature-test macros.

(since C++20)

[edit] Program utilities

Termination (e.g. std::abort, std::atexit), environment (e.g. std::system), signals (e.g. std::raise)

[edit] Dynamic memory management

Smart pointers (e.g. std::shared_ptr), allocators (e.g. std::allocator or std::pmr::memory_resource), C-style memory management (e.g. std::malloc)

[edit] Error handling

Exceptions (e.g. std::exception, std::terminate), assertions (e.g. assert)

[edit] Source code information capture

Defined in header <source_location>
(C++20)
 a class representing information about the source code, such as file names, line numbers, and function names
(class) [edit]

[edit] Initializer lists

Defined in header <initializer_list>
(C++11)
 references a temporary array created in list-initialization
(class template) [edit]

[edit] Three-way comparison

Defined in header <compare>
(C++20)
 specifies that operator <=> produces consistent result on given types
(concept) [edit]
(C++20)
 the result type of 3-way comparison that supports all 6 operators, is not substitutable, and allows incomparable values
(class) [edit]
(C++20)
 the result type of 3-way comparison that supports all 6 operators and is not substitutable
(class) [edit]
(C++20)
 the result type of 3-way comparison that supports all 6 operators and is substitutable
(class) [edit]
(C++20)
 named comparison functions
(function) [edit]
(C++20)
 constrained function object implementing x <=> y
(class) [edit]
(C++20)
 obtains the result type of the three-way comparison operator <=> on given types
(class template) [edit]
(C++20)
 the strongest comparison category to which all of the given types can be converted
(class template) [edit]
(C++20)
 performs 3-way comparison and produces a result of type std::strong_ordering
(customization point object)[edit]
(C++20)
 performs 3-way comparison and produces a result of type std::weak_ordering
(customization point object)[edit]
(C++20)
 performs 3-way comparison and produces a result of type std::partial_ordering
(customization point object)[edit]
(C++20)
 performs 3-way comparison and produces a result of type std::strong_ordering, even if operator<=> is unavailable
(customization point object)[edit]
(C++20)
 performs 3-way comparison and produces a result of type std::weak_ordering, even if operator<=> is unavailable
(customization point object)[edit]
(C++20)
 performs 3-way comparison and produces a result of type std::partial_ordering, even if operator<=> is unavailable
(customization point object)[edit]

[edit] Coroutine support

Types for coroutine support, e.g. std::coroutine_traits, std::coroutine_handle.

(since C++20)

[edit] Variadic functions

Support for functions that take an arbitrary number of parameters (via e.g. va_start, va_arg, va_end).

[edit] General-purpose utilities

[edit] Swap

Defined in header <utility>
swaps the values of two objects
(function template) [edit]
(C++14)
 replaces the argument with a new value and returns its previous value
(function template) [edit]
Defined in header <concepts>
(C++20)
 swaps the values of two objects
(customization point object)[edit]

[edit] Type operations

Defined in header <utility>
(C++11)
 forwards a function argument and use the type template argument to preserve its value category
(function template) [edit]
(C++23)
 forwards a function argument as if casting it to the value category and constness of the expression of specified type template argument
(function template) [edit]
(C++11)
 converts the argument to an xvalue
(function template) [edit]
(C++11)
 converts the argument to an xvalue if the move constructor does not throw
(function template) [edit]
(C++17)
 obtains a reference to const to its argument
(function template) [edit]
(C++11)
 obtains a reference to an object of the template type argument for use in an unevaluated context
(function template) [edit]
(C++23)
 converts an enumeration to its underlying type
(function template) [edit]

[edit] Integer comparison functions

Defined in header <utility>
(C++20)
 compares two integer values, ensuring that signed negative numbers are less than unsigned numbers
(function template) [edit]
(C++20)
 checks if an integer value is in the range of a given integer type
(function template) [edit]

[edit] Relational operators

Defined in header <utility>
Defined in namespace std::rel_ops
(deprecated in C++20)
 automatically generates comparison operators based on user-defined operator== and operator<
(function template) [edit]

[edit] Construction tags

Defined in header <utility>
(C++11)
 piecewise construction tag
(tag)[edit]
(C++17)
 in-place construction tag
(tag)[edit]
(C++26)
 value construction tag
(tag)[edit]

[edit] Pairs and tuples

Defined in header <utility>
implements binary tuple, i.e. a pair of values
(class template) [edit]
Defined in header <tuple>
(C++11)
 implements fixed size container, which holds elements of possibly different types
(class template) [edit]
(C++17)
 calls a function with a tuple of arguments
(function template) [edit]
(C++17)
 construct an object with a tuple of arguments
(function template) [edit]
Tuple protocol
Defined in header <tuple>
Defined in header <utility>
Defined in header <array>
Defined in header <ranges>
Defined in header <complex>
(C++11)
 obtains the number of elements of a tuple-like type
(class template) [edit]
(C++11)
 obtains the element types of a tuple-like type
(class template) [edit]

[edit] Sum types and type erased wrappers

Defined in header <optional>
(C++17)
 a wrapper that may or may not hold an object
(class template) [edit]
 
Defined in header <expected>
(C++23)
 a wrapper that contains either an expected or error value
(class template) [edit]
 
Defined in header <variant>
(C++17)
 a type-safe discriminated union
(class template) [edit]
 
Defined in header <any>
(C++17)
 objects that hold instances of any CopyConstructible type
(class) [edit]

[edit] Bitset

Defined in header <bitset>
implements constant length bit array
(class template) [edit]

[edit] Function objects

Partial function application (e.g. std::bind) and related utilities: utilities for binding such as std::ref and std::placeholders, polymorphic function wrappers: std::function, predefined functors (e.g. std::plus, std::equal_to), pointer-to-member to function converters std::mem_fn.

[edit] Hash support

Defined in header <functional>
(C++11)
 hash function object
(class template) [edit]

[edit] Date and time

Time tracking (e.g. std::chrono::time_point, std::chrono::duration), C-style date and time (e.g. std::time, std::clock)

[edit] Primitive string conversions

In addition to sophisticated locale-dependent parsers and formatters provided by the C++ I/O library, the C I/O library, C++ string converters, and C string converters, the header <charconv> provides light-weight, locale-independent, non-allocating, non-throwing parsers and formatters for arithmetic types.

Defined in header <charconv>
(C++17)
 converts an integer or floating-point value to a character sequence
(function) [edit]
(C++17)
 the return type of std::to_chars
(class) [edit]
(C++17)
 converts a character sequence to an integer or floating-point value
(function) [edit]
(C++17)
 the return type of std::from_chars
(class) [edit]
(C++17)
 specifies formatting for std::to_chars and std::from_chars
(enum) [edit]

[edit] Formatting library

Facilities for type-safe string formatting.

Defined in header <format>
(C++20)
 stores formatted representation of the arguments in a new string
(function template) [edit]
(C++20)
 writes out formatted representation of its arguments through an output iterator
(function template) [edit]
(C++20)
 writes out formatted representation of its arguments through an output iterator, not exceeding specified size
(function template) [edit]
(C++20)
 determines the number of characters necessary to store the formatted representation of its arguments
(function template) [edit]
(C++20)
 non-template variant of std::format using type-erased argument representation
(function) [edit]
(C++20)
 non-template variant of std::format_to using type-erased argument representation
(function template) [edit]
(C++20)
 defines formatting rules for a given type
(class template) [edit]
(C++20)
 exception type thrown on formatting errors
(class) [edit]

[edit] See also

C documentation for Utility library
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