std::experimental::source_location

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Technical specifications

Filesystem library (filesystem TS)

Library fundamentals (library fundamentals TS)

Library fundamentals 2 (library fundamentals 2 TS)

Extensions for parallelism (parallelism TS)

Extensions for parallelism 2 (parallelism TS v2)

Extensions for concurrency (concurrency TS)

Concepts (concepts TS)

Ranges (ranges TS)

Special mathematical functions (special math TR)

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

Defined in header <experimental/source_location>
struct source_location;		(library fundamentals TS v2)

The source_location class represents certain information about the source code, such as file names, line numbers, and function names. Previously, functions that desire to obtain this information about the call site (for logging, testing, or debugging purposes) must use function-style macros so that predefined macros like __LINE__ and __FILE__ are expanded in the context of the caller. The source_location class provides a better alternative.

Member functions

Creation
(constructor)	constructs a new source_location with implementation-defined values (public member function)
current [static]	constructs a new source_location (public static member function)
Other special member functions
(destructor) (implicitly declared)	destructs a source_location (public member function)
operator= (implicitly declared)	Implicitly declared copy/move assignment operators (public member function)
Field access
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)
function_name	return the name of the function represented by this object, if any (public member function)

Example

Run this code

#include <iostream>
#include <string_view>
#include <experimental/source_location>

void log(const std::string_view& message, const std::experimental::source_location& location = std::experimental::source_location::current())
{
    std::cout << "info:"
              << location.file_name() << ":"
              << location.line() << " "
              << message << '\n';
}

int main()
{
    log("Hello world!");
}

Possible output:

info:main.cpp:15 Hello world!