std::source_location::function_name

 

C++

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Utilities library

Language support Type support (basic types, RTTI, type traits) Library feature-test macros (C++20) Dynamic memory management Program utilities Error handling Coroutine support (C++20) Variadic functions launder (C++17) initializer_list (C++11) source_location (C++20) Three-way comparison (C++20) three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20) is_eqis_neqis_ltis_lteqis_gtis_gteq (C++20)(C++20)(C++20)(C++20)(C++20)(C++20)

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std::source_location

Member functions

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;		(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

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 <iostream>
#include <string_view>
#include <source_location>
 
inline void function_name(
    const std::string_view signature = "()",
    const std::source_location& location = std::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(); }
};
 
auto main() -> int
{
    foo();
    S p;
    S q{42};
    p = q;
    p = std::move(q);
}

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)