c++ - Remove trailing 0s and decimal if necessary from string -

i'm trying remove trailing zeros decimal, removing decimal if there no more trailing zeros.

this string produced boost's gmp_float string output of fixed.

this attempt, i'm getting std::out_of_range:

string trim_decimal( string toformat ){     while( toformat.find(".") && toformat.substr( toformat.length() - 1, 1) == "0" || toformat.substr( toformat.length() - 1, 1) == "." ){         toformat.pop_back();     }     return toformat; } 

how can remove trailing 0s if decimal present, removing decimal if there no more 0s after decimal point?

you need change to:

while( toformat.find(".")!=string::npos   // !=string::npos important!!!     && toformat.substr( toformat.length() - 1, 1) == "0"      || toformat.substr( toformat.length() - 1, 1) == "." ) {     toformat.pop_back(); } 

the key here add !=string::npos. when not found, std::basic_string::find() return std::basic_string::npos, not equal false (not expect).

static const size_type npos = -1;