C + + numeric--a summary of the method of converting between strings

There are several main methods of conversion in C + +:

(a), using the transformation function family in the CRT library.

_itoa, _itow and its reverse conversion atoi, _wtoi

_ltoa, _ltow and its reverse conversion atol, _wtol

_ultoa, _ultow

_ECVT, _FCVT, _GCVT and its reverse conversion

_atodbl, _atoldbl,_atoflt

... (Too much, don't want to write)

The advantage of using this method is that functions in the C standard library are readily available and portable (partially platform-dependent).

Disadvantages: Many conversion functions, the name is not uniform so difficult to remember, the use of inconvenient.

(b), with the help of the c++98 standard StringStream template class implementation.

The conversion of numeric values to strings can be implemented as follows:

template <typename CharT,typename NumericT>
basic_string<CharT>Numeric2String(NumericT num)
{
　　basic_ostringstream<CharT>oss;
　　oss << num;
　　return oss.str();
}

Where the chart type can be char or wchar_t, the corresponding return type is string and wstring. The numerict type can be an int, a long, float, etc built-in (build-in) numeric class, or a class type that overloads the operator << operator. Use like this:

string str=Numeric2String<char>(10);
wstring wstr=Numeric2String<wchar_t>(10.1f);

In the same vein, we can implement string to numeric conversions:

1.template <typename Numerict, TypeName chart>
2.NumericT string2numeric (const basic_string<chart> &STR)
3.{
4.     basic_istringstream<chart> ISS (str);
5.     numerict result;
6.     ISS >> result;
7. return result     ;
8.}