Utility library

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< cpp

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.


[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), type traits (e.g. std::is_integral, std::rank)

[edit] Dynamic memory management

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

[edit] Error handling

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

[edit] Initializer lists

allows the use of initializer list syntax to initialize non-aggregate types
(class template)

[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] Program utilities

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

[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] Bitset

implements constant length bit array

[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), method to function converters std::mem_fn.

[edit] std::optional

Class template representing a value that may or may not be present.

[edit] std::any

A type-safe container for single values of any type.

[edit] Pairs and tuples

implements binary tuple, i.e. a pair of values
(class template)
implements fixed size container, which holds elements of possibly different types
(class template)
calls a function with a tuple of arguments
(function template)
tag type used to select correct function overload for piecewise construction
an object of type piecewise_construct_t used to disambiguate functions for piecewise construction
implements compile-time sequence of integers
(class template)

[edit] Swap, forward and move

swaps the values of two objects
(function template)
replaces the argument with a new value and returns its previous value
(function template)
forwards a function argument
(function template)
obtains an rvalue reference
(function template)
obtains an rvalue reference if the move constructor does not throw
(function template)

[edit] Type operations

obtains a reference to its argument for use in unevaluated context
(function template)
obtains a reference to const to its argument
(function template)

[edit] Relational operators

Defined in namespace std::rel_ops
automatically generates comparison operators based on user-defined operator== and operator<
(function template)

[edit] Hash support

hash function object
(class template)