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Returns a pointer to the callable object stored in the function object.
Because function is a polymorphic wrapper class, it is unaware of the static type of its target callable object, and thus the template parameter TargetType must be explicitly specified.
TargetType shall match the target type, so that
Otherwise, a null pointer.
Output:
The pointer returned can be used to access or modify the target callable object.
Reference
C library:
- <cassert> (assert.h)
- <cctype> (ctype.h)
- <cerrno> (errno.h)
-
<cfenv> (fenv.h)C++11
- <cfloat> (float.h)
-
<cinttypes> (inttypes.h)C++11
- <ciso646> (iso646.h)
- <climits> (limits.h)
- <clocale> (locale.h)
- <cmath> (math.h)
- <csetjmp> (setjmp.h)
- <csignal> (signal.h)
- <cstdarg> (stdarg.h)
-
<cstdbool> (stdbool.h)C++11
- <cstddef> (stddef.h)
-
<cstdint> (stdint.h)C++11
- <cstdio> (stdio.h)
- <cstdlib> (stdlib.h)
- <cstring> (string.h)
-
<ctgmath> (tgmath.h)C++11
- <ctime> (time.h)
-
<cuchar> (uchar.h)C++11
- <cwchar> (wchar.h)
- <cwctype> (wctype.h)
Containers:
-
<array>C++11
- <deque>
-
<forward_list>C++11
- <list>
- <map>
- <queue>
- <set>
- <stack>
-
<unordered_map>C++11
-
<unordered_set>C++11
- <vector>
-
Input/Output:
Multi-threading:
-
<atomic>C++11
-
<condition_variable>C++11
-
<future>C++11
-
<mutex>C++11
-
<thread>C++11
-
Other:
- <algorithm>
- <bitset>
-
<chrono>C++11
-
<codecvt>C++11
- <complex>
- <exception>
- <functional>
-
<initializer_list>C++11
- <iterator>
- <limits>
- <locale>
- <memory>
- <new>
- <numeric>
-
<random>C++11
-
<ratio>C++11
-
<regex>C++11
- <stdexcept>
- <string>
-
<system_error>C++11
-
<tuple>C++11
-
<type_traits>C++11
-
<typeindex>C++11
- <typeinfo>
- <utility>
- <valarray>
<functional>
functions
wrapper classes
- binary_negate
-
functionC++11
-
reference_wrapperC++11
- unary_negate
operator classes
other classes
-
bad_function_callC++11
-
hashC++11
-
is_bind_expressionC++11
-
is_placeholderC++11
-
namespaces
-
placeholdersC++11
-
deprecated
function
-
function::~functionC++11
-
function::functionC++11
member functions
-
function::assignC++11
-
function::operator boolC++11
-
function::operator()C++11
-
function::operator=C++11
-
function::swapC++11
-
function::targetC++11
-
function::target_typeC++11
-
non-member overloads
-
relational operators (function)C++11
-
swap (function)C++11
-
- Reference
- <functional>
- function
- target
public member function
<functional>
std::function::target
template <class TargetType> TargetType* target() noexcept;template <class TargetType> const TargetType* target() const noexcept;
Get pointer to target
Because function is a polymorphic wrapper class, it is unaware of the static type of its target callable object, and thus the template parameter TargetType must be explicitly specified.
TargetType shall match the target type, so that
typeid(TargetType)==target_type()
. Otherwise, the function always returns a null pointer.Parameters
noneReturn value
A pointer to the target callable object, iftypeid(TargetType)
compares equal to the value returned by member target_type.Otherwise, a null pointer.
Example
|
|
Output:
120 120 120 120 80 |
Data races
Both the object and its target are accessed.The pointer returned can be used to access or modify the target callable object.
Exception safety
No-throw guarantee: this member function never throws exceptions.See also
- function::operator()
- Call target (public member function)
- function::target_type
- Target type_info (public member function)
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Spotted an error? contact us