reverse_conditional()

template<eve::relative_conditional_expr C, typename T >

constexpr auto eve::reverse_conditional ( C  c, eve::as< T >  tgt  )

constexpr

Required header: #include <eve/conditional.hpp>

For a given eve::relative_conditional_expr c, optimally computes the reverse eve::relative_conditional_expr for a given type T. For example, ignoring the first N lanes get reversed as ignoring the last N lanes.

Parameters

c	Condition to reverse
tgt	Wrapped type of the expected output

Returns

The exact semantic opposite of c with the same internal state.

Example

#include <iostream>
#include <eve/wide.hpp>
#include <eve/conditional.hpp>
 
int main()
{
  std::cout << eve::ignore_all << " -> "
            << eve::reverse_conditional(eve::ignore_all, eve::as(0)) << "\n";
 
  std::cout << eve::ignore_none << " -> "
            << eve::reverse_conditional(eve::ignore_none, eve::as(0)) << "\n";
 
  std::cout << eve::keep_first(1) << " -> "
            << eve::reverse_conditional(eve::keep_first(1), eve::as(0)) << "\n";
 
  std::cout << eve::ignore_last(1) << " -> "
            << eve::reverse_conditional(eve::ignore_last(1), eve::as(0)) << "\n";
}