How to implement input without enter in C++ console game - c++

Question

I am stuck with the input with no enter input.
I tried to use kbhit() + getch() from conio.h and it doesn't work on my system (Win10 and Ubuntu - unistd.h and termios.h). Program just skips block with these functions.
Then I used GetAsynkKeyState from windows.h. It works in the game (Level) though buggy, but doesn't in a Menu. Program as well skips (or something) block with input dispatch.
Menu input:
// The menu interface
bool Menu::SelectLevel() {
cout << "Select the level:" << endl;
size_t arrow_pos = 0;
// Prints level's names and char to exit the game
for (size_t i = 0; i <= _levels.size(); ++i) {
// Draw arrow before selected level
if (i == arrow_pos) {
cout << '>' << i + 1 << " - " << _levels[i].first[0] << endl;;
}
// Draw arrow before the exit select
else if (i == _levels.size() && i == arrow_pos) {
cout << '>' << "Exit" << endl;
}
// Draw the exit option
else if (i == _levels.size()) {
cout << ' ' << "Exit" << arrow_pos << endl;
}
// Draw levels list
else {
cout << ' ' << i + 1 << " - " << _levels[i].first[0] << endl;
}
}
// Input from keyboard TODO DOESN'T WORK!:
// If 's' pressed move arrow down
PoollingDelay(1);
if (GetAsyncKeyState(0x53) & 0x8000) {
++arrow_pos;
// If arrow reached top it goes to the bottom
if (arrow_pos == _levels.size() + 1) {
arrow_pos = 0;
}
}
// If 'w' pressed move arrow up
else if (GetAsyncKeyState(0x57) & 0x8000) {
--arrow_pos;
// If arrow reached bottom it goes to the top
if (arrow_pos == 65535) {
arrow_pos = _levels.size() + 1;
}
}
// If Return pressed
else if (GetAsyncKeyState(VK_RETURN) & 0x8000) {
// Don't think it would be worthy
if (arrow_pos < 1 || arrow_pos > _levels.size() - 1) {
throw runtime_error("Wrong select: " + to_string(arrow_pos));
}
// If player tired of this shit
if (arrow_pos == _levels.size() - 1) {
ClearTerminal();
return false;
}
// Play
PlayLevel(arrow_pos);
}
ClearTerminal();
return true;
}
Level input:
// TO DO DOESN'T WORK!:
void Level::ReadCommand() {
PoollingDelay(100);
if (GetAsyncKeyState(0x57)) {
Move(_NORTH);
}
else if (GetAsyncKeyState(0x41)) {
Move(_WEST);
}
else if (GetAsyncKeyState(0x53)) {
Move(_SOUTH);
}
else if (GetAsyncKeyState(0x44)) {
Move(_EAST);
}
else if (GetAsyncKeyState(0x45)) {
throw runtime_error(exit_the_lvl);
}
}

Answer 1

Short answer: you can't using only C++ and its standard library.
This is because the language is not designed to handle low-level hardware events. To do this, you need to rely on a separate library, dedicated to handle I/O. Lots of them, some are more or less easy to integrate. For simple games, SDL is nice.