std::source_location::source_location

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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

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

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