[Basic C++]

base.cpp

// https://isocpp.org/images/uploads/2-Tour-Basics.pdf

std::cout << __func__ << __FILE__ << __LINE__ << std::endl;

// XXX scalar vs aggregate
const auto foo { 42 }; // valid but {} hints at aggregate (in theory)
const auto foo = 42;
const auto str { "foo" };


struct Ruler {
	std::string name {};
    int reign_begin {};
	int reign_end {};
};

// MEMORY MANAGEMENT
// https://isocpp.org/wiki/faq/freestore-mgmt

// - if you need an auto-free in scope, use the stack!!
const Ruler from_stack{ .name{"Clovis I"},     .reign_begin=509, .reign_end=511}; // https://en.cppreference.com/w/cpp/language/aggregate_initialization
// - make_unique (or make_shared) are nearly always superior to both new/malloc() and completely eliminate delete/free()
auto from_unique = std::make_unique<Ruler>(Ruler{ .title{"king"}, .name{"Clovis I"},     .reign_begin=509, .reign_end=511});
*from_unique.get();
// - new -> delete
const Ruler* from_new = new Ruler{ .name{"Clovis I"},     .reign_begin=509, .reign_end=511};
delete from_new; from_new = nullptr;
// - malloc() -> free()

  
// https://stackoverflow.com/a/67967472/587407
int* x = new int[5];          // gv gv gv gv gv (gv - garbage value)
int* x = new int[5]();        // 0  0  0  0  0 
int* x = new int[5]{};        // 0  0  0  0  0  (Modern C++)
int* x = new int[5]{1,2,3};   // 1  2  3  0  0  (Modern C++)

char* p = new (std::nothrow) char [1048576];
)if (!p) { /*...*/ } // null pointers are implicitly converted to false
delete p; p = nullptr;

////////////
enum class Color { red, blue, green }; // enum class hides the "enum"
Color col = Color::red; // no need to mention "enum" 👍
Color next = static_cast<Color>((static_cast<int>(col) + 1) % 3); // DANGER

////////////
switch (answer) {
case ’y’:
	return true;
case ’n’:
	return false;
default:
	cout << "Sorry, I don’t understand that.\n";
	++tries; // increment
}

////////////
// lambdas
// https://learn.microsoft.com/en-us/cpp/cpp/lambda-expressions-in-cpp
// XXX mutable by copy!! https://stackoverflow.com/a/43129100/587407

////////////
// tuples


// exceptions
// https://learn.microsoft.com/en-us/cpp/cpp/errors-and-exception-handling-modern-cpp
#include <exception>;
throw std::invalid_argument("MyFunc argument too large.");
try
  {
    //...
  }
  catch (std::exception& e)
  {
    std::cerr << "exception caught: " << e.what() << std::endl;
  }