`defaulted` constructor in C++

You have seen Foo() = default;. It declares a default constructor (duh!). But what does it really do, and when is it actually useful? "When is it useful" is a very interesting question in my opinion because next time when you see = default; in other people's code, you would understand why…

C++ exception (3) – catching an exception

This is the third post of a series that I am making on C++ exceptions. C++ exception (1) — zero-cost exception handlingThis is the first post of a series I am making on C++ exceptions. C++ exception (1) — zero-cost exception handlingThis is the first post of a series I am making…

C++ exception (2) — throwing an exception

This is the second post of a series that I am making on C++ exceptions. C++ exception (1) — zero-cost exception handlingThis is the first post of a series I am making on C++ exceptions. C++ exception (1) — zero-cost exception handlingThis is the first post of a series I am making…

C++ exception (1) — zero-cost exception handling

This is the first post of a series I am making on C++ exceptions. C++ exception (1) — zero-cost exception handlingThis is the first post of a series I am making on C++ exceptions. C++ exception (2) — throwing an exceptionThis is the second post of a series that I am making…

`struct Foo f;` and `struct Foo f{};` are very different

Compare the following two programs, and can you predict what the outputs would be for each? // program #1 struct Foo { int x; }; void stack() { int x = 3; } void bar() { struct Foo foo{}; cout << foo.x << endl; } int main() { stack(); bar(); return 0; } // program #2 struct Foo { int x; }; void stack(…

When would someone use std::enable_shared_from_this

std::enable_shared_from_this [https://en.cppreference.com/w/cpp/memory/enable_shared_from_this] allows a class to have a valid shared_ptr of this. Simply adding a member function that returns shared_ptr(this) is susceptible to double-free. But when would you use such a feature?…

Build `folly::coro` with GCC

You have heard about Coroutine in C++, and you want to use it. There're two coroutine implementations that are considered most mature - cppcoro and folly::coro. They are written by the same guy - Lewis Baker. He's brilliant, and you shoud watch his cppcon talk on structured concurrency [https:…

Why you don't need virtual base destructor with smart pointers

struct Foo { // virtual ~Foo() {}; int a; }; struct Bar : public Foo { ~Bar() {std::cout << "bar dtor" << std::endl;}; }; int main() { std::shared_ptr f = std::make_shared(); //Foo* f = new Bar(); return 0; } In this example, the shared_ptr version would work as you expect. The raw pointer version…