retornando o tamanho do arquivo

long getSize(string name)
{

    FILE* arch = fopen(&name[0], "r");
    long actualPos = ftell(arch);
    long sizeArch;

    fseek(arch, 0, SEEK_END);
    sizeArch = ftell(arch);

    fseek(arch, actualPos, SEEK_SET);
    fclose(arch);


    return sizeArch;
}