'argument' : conversion from 'int' to 'char', possible loss of data

[nn1436401@…]

boost_program_options.1.55.0.16\lib\native\src\parsers.cpp(223): warning C4242: 'argument' : conversion from 'int' to 'char', possible loss of data

tolower returns 'int' and not 'char'. The cast must be used:

result += static_cast<char>(tolower(s[n]));

                string result;
                if (s.find(prefix) == 0) {
                    for(string::size_type n = prefix.size(); n < s.size(); ++n) 
                    {   
                        // Intel-Win-7.1 does not understand
            // push_back on string.         
                        result += tolower(s[n]);
                    }

P.S. Also it is better to use boost algorithm tolower on string rather than writing it by ourselves.

[Vladimir Prus]

This was previously fixed in ​https://github.com/boostorg/program_options/commit/3ce1c74a0f0257d291c47e28bd2bae8385b69225