Author’s note This is an optional lesson. We recommend having a light read-through to familiarize yourself with the material, but comprehensive understanding is not required to proceed with future lessons. In lesson , we discussed how calling access functions that return references to data members can be dangerous when the …
In lesson , we covered return by reference. In particular, we noted, “The object being returned by reference must exist after the function returns”. This means we should not return local variables by reference, as the reference will be left dangling after the local variable is destroyed. However, it is …
In lesson , we discussed how type aliases let us define an alias for an existing type. Creating a type alias for a class template where all template arguments are explicitly specified works just like a normal type alias: #include <iostream> template <typename T> struct Pair { T first{}; T …
In the prior lesson (), we discussed C-style multidimensional arrays. // C-style 2d array int arr[3][4] { { 1, 2, 3, 4 }, { 5, 6, 7, 8 }, { 9, 10, 11, 12 }}; But as you’re aware, we generally want to avoid C-style arrays (unless they are being …
In lesson , we discussed arrays and enumerations. Now that we have constexpr std::array in our toolkit, we’re going to continue that discussion and show a few additional tricks. Using static assert to ensure the proper number of array initializers When initializing a constexpr std::array using CTAD, the compiler will …
In the prior lesson, we mentioned that arrays can have elements of any object type. This includes objects with fundamental types (e.g. int) and objects with compound types (e.g. pointer to int). #include <array> #include <iostream> #include <vector> int main() { int x { 1 }; int y { 2 …
A std::array isn’t limited to elements of fundamental types. Rather, the elements of a std::array can be any object type, including compound types. This means you can create a std::array of pointers, or a std::array of structs (or classes) However, initializing a std::array of structs or classes tends to trip …
An object of type std::array can be passed to a function just like any other object. That means if we pass a std::array by value, an expensive copy will be made. Therefore, we typically pass std::array by (const) reference to avoid such copies. With a std::array, both the element type …
In lesson , we discussed the unfortunate decision to make the standard library container classes use unsigned values for lengths and indices. Because std::array is a standard library container class, it is subject to the same issues. In this lesson, we’ll recap ways to index and get the length of …
Words of encouragement This chapter isn’t an easy one. We covered a lot of material, and unearthed some of C++’s warts. Congrats on making it through! Arrays are one of the keys that unlock a huge amount of power within your C++ programs. Chapter Review A container is a data …
