A constructor defines how an object is created. That matters because construction is the first chance a class has to put itself into a valid state. C++ supports several constructor patterns, and each one solves a slightly different problem. Three…
A constructor’s member initializer list can mislead you if you read it left to right. Because the C++ standard says so, data members are not initialized in the order they appear in the member initializer list. They are initialized in…
Introduction Encapsulation is a technique used to enforce the separation of interface and implementation by hiding (making inaccessible) the implementation of a program-defined data type from users. We use access specifiers to achieve this objective. Consider a classic OOP-based class…
private does not mean “only this object can access this member.” It means “only this class and its friends can access this member.” That distinction matters because one object of a class can access the private members of another object of…
Just like with fundamental types, program-defined types can be labelled const. In doing so, the members become immutable. const applies to the whole object Consider this struct: We can create a const instance: Despite sampleRateHz not being const it still has the…
The problem Suppose we have a generic Reading type: The repeated type is the problem: It is technically correct, but it is very long. Creating an alias template An alias template looks like this: Value remains flexible. The timestamp type and source type…
Sometimes a function or container needs to keep two related values together. You could write your own small struct, but there’s no need to reinvent the wheel. C++ already provides a simple standard option: std::pair. It is a class template from <utility> that…
Examine the program below: We have to duplicate the struct and function just to support another type. What if we want the program to be compatible with more types like float? Clearly this doesn’t scale. We can do better. Class…
A struct’s size is not always the sum of its members. The compiler may insert unused bytes between members so each member is placed at an address suitable for its alignment requirement. Those unused bytes are called padding, and they can…
C++ is very adamant with functions returning a single type. To circumvent this, out parameters can be used. However, #100 – Why you should avoid using out parameters condones their use. Fortunately, there is a workaround. Passing structs (by reference)…