Case insensitive string comparison C++ [duplicate]

Answer 1

You can write a simple function to convert the existing string to lower case as follows:

#include 
#include 
#include 
#include 
#include 

std::string make_lowercase( const std::string& in )
{
  std::string out;

  std::transform( in.begin(), in.end(), std::back_inserter( out ), ::tolower );
  return out;
}

int main()
{
  if( make_lowercase( "Hello, World!" ) == std::string( "hello, world!" ) ) {
    std::cout << "match found" << std::endl;
  }

  return 0;
}