Command Dispatch

An enum and a switch make command handling explicit.

command_dispatch.cpp

#include <iostream>

enum class Command {
    Start,
    Stop,
    Pause
};

Command decode(int code) {
    if (code == 1) {
        return Command::Start;
    }
    if (code == 2) {
        return Command::Stop;
    }
    return Command::Pause;
}

int main() {
    int code = ;

    Command command = decode(code);
    int action = 0;
    switch (command) {
        case Command::Start:
            action = 10;
            break;
        case Command::Stop:
            action = 20;
            break;
        case Command::Pause:
            action = 30;
            break;
    }

    std::cout << "code=" << code << std::endl;
    std::cout << "action=" << action << std::endl;
    return 0;
}

#include <iostream>

enum class Command {
    Start,
    Stop,
    Pause
};

Command decode(int code) {
    if (code == 1) {
        return Command::Start;
    }
    if (code == 2) {
        return Command::Stop;
    }
    return Command::Pause;
}

int main() {
    int code = ;

    Command command = decode(code);
    int action = 0;
    switch (command) {
        case Command::Start:
            action = 10;
            break;
        case Command::Stop:
            action = 20;
            break;
        case Command::Pause:
            action = 30;
            break;
    }

    std::cout << "code=" << code << std::endl;
    std::cout << "action=" << action << std::endl;
    return 0;
}

#include <iostream>

enum class Command {
    Start,
    Stop,
    Pause
};

Command decode(int code) {
    if (code == 1) {
        return Command::Start;
    }
    if (code == 2) {
        return Command::Stop;
    }
    return Command::Pause;
}

int main() {
    int code = ;

    Command command = decode(code);
    int action = 0;
    switch (command) {
        case Command::Start:
            action = 10;
            break;
        case Command::Stop:
            action = 20;
            break;
        case Command::Pause:
            action = 30;
            break;
    }

    std::cout << "code=" << code << std::endl;
    std::cout << "action=" << action << std::endl;
    return 0;
}

enum Use an enum when a value must be one of a small named set.

dispatch A switch turns the command into the project action that should happen next.