Function objects
From cppreference.com
A function object is any object for which the function call operator is defined. C++ provides many built-in function objects as well as support for creation and manipulation of new function objects.
Polymorphic function wrappers
std::function provides support for storing arbitrary function objects.
| (C++11) |
wraps callable object of any type with specified function call signature (class template) |
| (C++11) |
creates a function object out of a pointer to a member (function template) |
| (C++11) |
the exception thrown when invoking an empty std::function (class) |
| (C++17) |
invokes any Callable object with given arguments (function template) |
Bind
std::bind provides support for partial function application, i.e. binding arguments to functions to produce new functions.
| (C++11) |
binds one or more arguments to a function object (function template) |
| (C++11) |
indicates that an object is std::bind expression or can be used as one (class template) |
| (C++11) |
indicates that an object is a standard placeholder or can be used as one (class template) |
| Defined in namespace
std::placeholders | |
| (C++11) |
placeholders for the unbound arguments in a std::bind expression (constant) |
Negators
std::not_fn creates a function object that negates the result of the callable object passed to it.
| (C++17) |
Creates a function object that returns the complement of the result of the function object it holds (function template) |
| (deprecated) |
wrapper function object returning the complement of the unary predicate it holds (class template) |
| (deprecated) |
wrapper function object returning the complement of the binary predicate it holds (class template) |
| (deprecated) |
constructs custom std::unary_negate object (function template) |
| (deprecated) |
constructs custom std::binary_negate object (function template) |
Searchers
Searchers implementing several string searching algorithms are provided and can be used either directly or with std::search.
| (C++17) |
standard C++ library search algorithm implementation (class template) |
| (C++17) |
Boyer-Moore search algorithm implementation (class template) |
| Boyer-Moore-Horspool search algorithm implementation (class template) |
Reference wrappers
Reference wrappers allow reference arguments to be stored in copyable function objects:
| (C++11) |
CopyConstructible and CopyAssignable reference wrapper (class template) |
| (C++11)(C++11) |
creates a std::reference_wrapper with a type deduced from its argument (function template) |
Operator function objects
C++ defines several function objects that represent common arithmetic and logical operations:
Arithmetic operations | |
| function object implementing x + y (class template) | |
| function object implementing x - y (class template) | |
| function object implementing x * y (class template) | |
| function object implementing x / y (class template) | |
| function object implementing x % y (class template) | |
| function object implementing -x (class template) | |
Comparisons | |
| function object implementing x == y (class template) | |
| function object implementing x != y (class template) | |
| function object implementing x > y (class template) | |
| function object implementing x < y (class template) | |
| function object implementing x >= y (class template) | |
| function object implementing x <= y (class template) | |
Logical operations | |
| function object implementing x && y (class template) | |
| function object implementing x || y (class template) | |
| function object implementing !x (class template) | |
Bitwise operations | |
| function object implementing x & y (class template) | |
| function object implementing x | y (class template) | |
| function object implementing x ^ y (class template) | |
| (C++14) |
function object implementing ~x (class template) |
Old binders and adaptors
Several utilities that provided early functional support are deprecated in C++11 and removed in C++17:
Base | |
| (until C++17) |
adaptor-compatible unary function base class (class template) |
| (until C++17) |
adaptor-compatible binary function base class (class template) |
Binders | |
| (until C++17)(until C++17) |
function object holding a binary function and one of its arguments (class template) |
| (until C++17)(until C++17) |
binds one argument to a binary function (function template) |
Function adaptors | |
| (until C++17) |
adaptor-compatible wrapper for a pointer to unary function (class template) |
| (until C++17) |
adaptor-compatible wrapper for a pointer to binary function (class template) |
| (until C++17) |
creates an adaptor-compatible function object wrapper from a pointer to function (function template) |
| (until C++17)(until C++17)(until C++17)(until C++17) |
wrapper for a pointer to nullary or unary member function, callable with a pointer to object (class template) |
| (until C++17) |
creates a wrapper from a pointer to member function, callable with a pointer to object (function template) |
| (until C++17)(until C++17)(until C++17)(until C++17) |
wrapper for a pointer to nullary or unary member function, callable with a reference to object (class template) |
| (until C++17) |
creates a wrapper from a pointer to member function, callable with a reference to object (function template) |