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In the C++ programming language, the assignment operator, =, is the operator used for assignment.Like most other operators in C++, it can be overloaded.. The copy assignment operator, often just called the "assignment operator", is a special case of assignment operator where the source (right-hand side) and destination (left-hand side) are of the same class type.
Copy constructor if no move constructor and move assignment operator are explicitly declared. If a destructor is declared generation of a copy constructor is deprecated (C++11, proposal N3242 [2]). Move constructor if no copy constructor, copy assignment operator, move assignment operator and destructor are explicitly declared.
For function that manipulate strings, modern object-oriented languages, like C# and Java have immutable strings and return a copy (in newly allocated dynamic memory), while others, like C manipulate the original string unless the programmer copies data to a new string.
In this case chain assignment can be implemented by having a right-associative assignment, and assignments happen right-to-left. For example, i = arr[i] = f() is equivalent to arr[i] = f(); i = arr[i]. In C++ they are also available for values of class types by declaring the appropriate return type for the assignment operator.
All the operators (except typeof) listed exist in C++; the column "Included in C", states whether an operator is also present in C. Note that C does not support operator overloading. When not overloaded, for the operators && , || , and , (the comma operator ), there is a sequence point after the evaluation of the first operand.
A basic example is in the argv argument to the main function in C (and C++), which is given in the prototype as char **argv—this is because the variable argv itself is a pointer to an array of strings (an array of arrays), so *argv is a pointer to the 0th string (by convention the name of the program), and **argv is the 0th character of the ...
The std::string type is the main string datatype in standard C++ since 1998, but it was not always part of C++. From C, C++ inherited the convention of using null-terminated strings that are handled by a pointer to their first element, and a library of functions that manipulate such strings.
A compiler can implement operators and functions with subroutine calls or with inline code. Some built-in operators supported by a language have a direct mapping to a small number of instructions commonly found on central processing units, though others (e.g. '+' used to express string concatenation) may have complicated implementations.