如何将 std: : string 转换为小写？

Question

I want to convert a std::string to lowercase. I am aware of the function tolower(), however in the past I have had issues with this function and it is hardly ideal anyway as use with a std::string would require iterating over each character.

Is there an alternative which works 100% of the time?

转载于:https://stackoverflow.com/questions/313970/how-to-convert-stdstring-to-lower-case

Answer 1

There is a Boost string algorithm for this:

#include <boost/algorithm/string.hpp>    

std::string str = "HELLO, WORLD!";
boost::algorithm::to_lower(str); // modifies str

Or, for non-in-place:

#include <boost/algorithm/string.hpp>    

const std::string str = "HELLO, WORLD!";
const std::string lower_str = boost::algorithm::to_lower_copy(str);