Converting string to __int64

How can I do that? Are there any standard functions I can use, or I have to make my own functions for that.

What compiler do you use.

Dev-C++ (MinGW).

Well I don't know without testing, but if iostream's do not work for the conversions, then you can test cstdio functions with formatting flags %lld %llu %I64d %I64u.

I found _atoi64() and _i64toa().

Ya - those aren't standard.

__int64 is not standard (nor is long long); there is no standard way to convert to a nonstandard type.

There is also no standard integral type guaranteed to be 64 bits or larger.