operator[]()

template<concepts::option... Opts>

template<concepts::keyword Key>

auto rbr::settings< Opts >::operator[] ( Key const & k ) const

inlineconstexprnoexcept

Retrieved a value via a keyword.

Retrieve the value bound to a given keyword k inside current rbr::settings instance. If such a keyword is not present, either an instance of rbr::unknown_key is returned or a default value or function call will be returned.

Parameters

k	Keywords to check

Returns

If any, the value bound to k.

Example:

#include <raberu/raberu.hpp>
#include <iostream>
 
int main()
{
  using namespace rbr::literals;
 
  int i = 77;
  auto values = rbr::settings("size"_kw = 75ULL, "transparent"_fl);
 
  std::cout << values["size"_kw] << "\n";
  std::cout << values["transparent"_fl] << "\n";
  std::cout << values["value"_kw | 13.37] << "\n";
  std::cout << values["modal"_fl | rbr::call([&]() { return i++; })] << "\n\n";
 
  std::cout << "i = " << i << "\n";
}