Understanding exception support in C++

C++ exceptions provide a mechanism for reporting errors in a thread-safe manner, without the need to manually unwind the call stack, while also providing support for RAII and complex data types. To better understand this, refer to the following example:

#include <cstring>
#include <iostream>

void myfunc(int val)
{
    if (val == 42) {
        throw EINVAL;
    }
}

int main()
{
    try {
        myfunc(1);
        std::cout << "success\n";

        myfunc(42);
        std::cout << "success\n";
    }
    catch(int ret) {
        std::cout << "failure: " << strerror(ret) << '\n';
    }
}

// > g++ -std=c++17 scratchpad.cpp; ./a.out
// success
// failure: Invalid argument

In the preceding example, our myfunc() function has been greatly simplified compared to its POSIX-style equivalent...