[C/C++] Cross platform - Convert std::string to std::wstring and vice versa - conver string and wstring to int/long

This is one of the easiest way to convert a std::string to std::wstring and vice versa:

1. Convert string to wstring:

std::string myString = " This is test string";
std::wstring wideString( myString.begin(), myString.end());

or

std::string myString = " This is test string";
std::wstring wideString;
wideString.assign( myString.begin(), myString.end());

2. Convert wstring to string - Similar to converting string to wstring


std::string wideString= L" This is wide string";
std::wstring asciiString( wideString.begin(), wideString.end());

or


std::string wideString= L" This is test string";
std::wstring asciiString;
asciiString.assign( wideString.begin(), wideString.end());

3. convert wstring to integer
int myInt;
wstring myString;

myInt = wcstol( myString.c_str(), NULL, 10);

read more about this function here: http://www.cplusplus.com/reference/cwchar/wcstol/.

[C/C++] Check if a file exists or not

you can use fopen("file_name", "w+"); to check if a file exist or not.

For more checking option, such as check access level you can use  access(), e.g.:

#include <unistd.h>

int res = access(path, R_OK);
if (res < 0) {
    if (errno == ENOENT) {
         // file does not exist
    } else if (errno == EACCES]) {
         // file exists but is not readable
    } else {
         // uh oh
    }
}