std::experimental::source_location::function_name

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Experimental

Technical Specification

Filesystem library (filesystem TS)

Library fundamentals (library fundamentals TS)

Library fundamentals 2 (library fundamentals TS v2)

Library fundamentals 3 (library fundamentals TS v3)

Extensions for parallelism (parallelism TS)

Extensions for parallelism 2 (parallelism TS v2)

Extensions for concurrency (concurrency TS)

Extensions for concurrency 2 (concurrency TS v2)

Concepts (concepts TS)

Ranges (ranges TS)

Reflection (reflection TS)

Mathematical special functions (special functions TR)

Experimental Non-TS

Pattern Matching

Linear Algebra

std::execution

Contracts

2D Graphics

 

Library fundamentals v2

experimental::propagate_const

experimental::not_fn

experimental::observer_ptr

experimental::make_array

experimental::to_array

experimental::ostream_joiner

experimental::gcd

experimental::lcm

experimental::source_location

experimental::randint

detection idiom

uniform container erasure

logical operator type traits

 

std::experimental::source_location

Creation

source_location::source_location

source_location::current

Field Access

source_location::line

source_location::column

source_location::file_name

source_location::function_name

 

constexpr const char* function_name() const noexcept;		(library fundamentals TS v2)

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

The following example shows how it is possible to use the std::source_location::function_name() to print a name of a function, constructor, destructor, or overloaded operator().

Run this code

#include <experimental/source_location>
#include <iostream>
#include <string_view>
 
inline void function_name(
    const std::string_view signature = "()",
    const std::experimental::source_location& location
        = std::experimental::source_location::current())
{
    std::cout
        << location.function_name() // <- name of the caller!
        << signature
        << '\n';
}
 
void foo() { function_name(); }
 
struct S {
    S() { function_name(); }
    S(int) { function_name("(int)"); }
    S& operator=(S const&) { function_name("(const S&)"); return *this; }
    S& operator=(S&&) { function_name("(S&&)"); return *this; }
    ~S() { function_name(); }
};
 
int main()
{
    foo();
    S p;
    S q{42};
    p = q;
    p = std::move(q);
}

Possible output:

foo()
S()
S(int)
operator=(const S&)
operator=(S&&)
~S()
~S()

See also

line	return the line number represented by this object (public member function)
column	return the column number represented by this object (public member function)
file_name	return the file name represented by this object (public member function)
C++ documentation for Filename and line information