std::source_location:: function_name

From cppreference.com
C++
Utilities library
General utilities
Relational operators (deprecated in C++20)
std::source_location
constexpr const char * function_name ( ) const noexcept ;
(since C++20)

Returns the name of the function associated with the position represented by this object, if any.

Parameters

(none)

Return value

If this object represents a position in a body of a function, returns an implementation-defined null-terminated byte string corresponding to the name of the function.

Otherwise, an empty string is returned.

Example

std::source_location::function_name may help to obtain the names of functions (including the special functions) alongside with their signatures.

Run this code 
#include <cstdio>
#include <utility>
#include <source_location>
 
inline void print_function_name(
    const std::source_location& location = std::source_location::current())
{
    std::puts(location.function_name()); // prints the name of the caller
}
 
void foo(double &&) { print_function_name(); }
 
namespace bar { void baz() { print_function_name(); } }
 
template <typename T> auto pub(T) { print_function_name(); return 42; }
 
struct S {
    S() { print_function_name(); }
    S(int) { print_function_name(); }
    ~S() { print_function_name(); }
    S& operator=(S const&) { print_function_name(); return *this; }
    S& operator=(S&&) { print_function_name(); return *this; }
};
 
int main(int, char const* const[])
{
    print_function_name();
    foo(3.14);
    bar::baz();
    pub(0xFULL);
    S p;
    S q{42};
    p = q;
    p = std::move(q);
    [] { print_function_name(); }();
}

Possible output: 

int main(int, const char* const*)
void foo(double&&)
void bar::baz()
auto pub(T) [with T = long long unsigned int]
S::S()
S::S(int)
S& S::operator=(const S&)
S& S::operator=(S&&)
main(int, const char* const*)::<lambda()>
S::~S()
S::~S()

See also

return the line number represented by this object
(public member function)
return the column number represented by this object
(public member function)
return the file name represented by this object
(public member function)
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