std::experimental::source_location::line

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Technical specifications
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)
 
 
 
constexpr std::uint_least32_t line() const noexcept;
(library fundamentals TS v2)

Returns the line number represented by this object.

Parameters

(none)

Return value

The line number represented by this object.

Example

#include <experimental/source_location>
#include <string_view>
#include <iostream>
using std::experimental::source_location;
 
inline void cur_line(
    const std::string_view message = "",
    const source_location& location = source_location::current())
{
    std::cout
        << location.line() // <- the call-site line #
        << ") "
        << message; 
}
 
auto main() -> int
{
    cur_line("++" "\n");
    cur_line(); std::cout << "Hello," "\n";
    cur_line(); std::cout << "C++20!" "\n";
    cur_line("--" "\n");
}

Output:

18) ++
19) Hello,
20) C++20!
21) --

See also

return the column number represented by this object
(public member function)
return the file name represented by this object
(public member function)
return the name of the function represented by this object, if any
(public member function)