C++ IsFloat function


Does anybody know of a convenient means of determining if a string value "qualifies" as a floating-point number?

bool IsFloat( string MyString )
   ... etc ...

   return ... // true if float; false otherwise

Best Solution

If you can't use a Boost library function, you can write your own isFloat function like this.

#include <string>
#include <sstream>

bool isFloat( string myString ) {
    std::istringstream iss(myString);
    float f;
    iss >> noskipws >> f; // noskipws considers leading whitespace invalid
    // Check the entire string was consumed and if either failbit or badbit is set
    return iss.eof() && !iss.fail();