What does the explicit keyword mean in C++?

The explicit keyword in C++ is used to mark constructors to not implicitly convert types. For example, if you have a class Foo −

class Foo {
public:
    Foo(int n); // allocates n bytes to the Foo object
    Foo(const char *p); // initialize object with char *p
};

Now if you try

Foo mystring = 'x';

The char 'x' is implicitly converted to int and then will call the Foo(int) constructor. But this is not what was intended. So to prevent such conditions and make the code less error-prone, define the constructor as explicit −

Example 

class Foo {
   public:
      explicit Foo (int n); //allocate n bytes
      Foo(const char *p); // initialize with string p
};

Nikitha N

Published on 28-Feb-2018 10:56:28

• Related Questions & Answers
• What does the restrict keyword mean in C++?
• What does the volatile keyword mean in C++?
• What does the KEY keyword mean in MySQL?
• Use of explicit keyword in C++
• What does explicit wait perform?
• What does the keyword var do in C#?
• What does the [Flags] Enum Attribute mean in C#?
• What does the operation c=a+++b mean in C/C++?
• What does the two question marks together (??) mean in C#?
• What does an auto keyword do in C++?
• What does these operators mean (** , ^ , %, //) ?
• What does the Star operator mean in Python?
• What does Kicking the Tires mean in Investment?
• What does createdCollectionAutomatically mean in MongoDB?
• What does operator ~= mean in Lua?