NAME¶

std::source_location::source_location - std::source_location::source_location

Synopsis¶

constexpr source_location() noexcept; (1) (since C++20)
source_location( const source_location& other ); (2) (since C++20)
source_location( source_location&& other ) noexcept; (3) (since C++20)

1) Constructs a source_location object of unspecified value.
2,3) Copy and move constructors. It is unspecified whether they are trivial and/or
constexpr.

Parameters¶

other - another source_location to copy or move from

Example¶

// Run this code

#include <iomanip>
#include <iostream>
#include <ranges>
#include <source_location>
#include <string_view>
#include <vector>

// GCC specific type name printer
#if (__GNUG__ >= 11)
template<typename T>
auto type_name_helper(const std::source_location s = std::source_location::current())
{
using std::operator""sv;
const std::string_view fun_name{s.function_name()};
constexpr auto prefix{"[with T = "sv};
const auto type_name_begin{fun_name.find(prefix)};
if (""sv.npos == type_name_begin)
return ""sv;
const std::size_t first{type_name_begin + prefix.length()};
return std::string_view{fun_name.cbegin() + first, fun_name.cend() - 1};
}

template<typename T>
auto type_name() { return type_name_helper<T>(); }
#endif

void print(std::string_view const comment, std::source_location const l)
{
std::cout << comment << ":\n"
<< " file_name : " << std::quoted(l.file_name()) << '\n'
<< " function_name : " << std::quoted(l.function_name()) << '\n'
<< " line : " << l.line() << '\n'
<< " column : " << l.column() << '\n';
}

int main()
{
constexpr std::source_location default_constructed;
print("default constructed", default_constructed);

constexpr std::source_location current = std::source_location::current();
print("current", current);

#if (__GNUG__ >= 11)
const std::vector<std::vector<int>> v{{1,2}, {3,4,5}, {6}};
auto jv = std::ranges::join_view(v);
std::cout << '\n'
<< '[' << type_name<int>() << "]\n"
<< '[' << type_name<double*>() << "]\n"
<< '[' << type_name<decltype([](){})>() << "]\n"
<< '[' << type_name<decltype(type_name<int>())>() << "]\n"
<< '[' << type_name<decltype(jv)>() << "]\n";
#endif
}

Possible output:¶

default constructed:
file_name : ""
function_name : ""
line : 0
column : 0
current:
file_name : "main.cpp"
function_name : "int main()"
line : 39
column : 75

[int]
[double*]
[main()::<lambda()>]
[std::basic_string_view<char>]
[std::ranges::join_view<std::ranges::ref_view<const std::vector<std::vector<int> > > >]

See also¶

current constructs a new source_location corresponding to the location of the
[static] call site
(public static member function)
constructor constructs a new stacktrace_entry
(C++23) (public member function of std::stacktrace_entry)