Operator overloading (operator syntax and overloading generally) is usually only syntactic sugar.
Because operator overloading allows the programmer to change the usual semantics of an operator, it is usually considered good practice to use operator overloading with care.
A classification of some programming languages by whether their operators are overloadable by the programmer and whether the operators are limited to a predefined set.
Binary operator functions that are members of the class take a single argument, which is the right- hand side of the operator expression.
By defining an operator overload function as a friend, the class instance pointer is not passed to the function.
The definition of the friend operator+ function is similar to the member function, except that it does not take an implied pointer to the current instance of the class as the first argument, and the body of the function has to refer to each argument explicitly.
In this case we overload the + operator and the * operator, with the declarations in lines 10 through 12, and the definitions in lines 16 through 40.
The header in line 16 illustrates the first overloading where the + operator is overloaded by giving the return type followed by the keyword operator and the operator we wish to overload.
The operations within the method implementation can be anything we need them to be, and they are usually much more meaningful than the silly math included here.
Posted - 7/21/2004 8:58:04 AM operator+ has to create a copy somewhere, otherwise it would be no different to operator+=, creating a copy in the parameter seems like as good a place as any to create it.
operator+ has to create a copy somewhere, otherwise it would be no different to operator+=, creating a copy in the parameter seems like as good a place as any to create it.
If you get a problem with your delete operation, then it is because you're either deleting something that shouldn't be (invalid pointer or already deleted) or memory has been overwritten somewhere.
Programmers who are used to a programming language which doesn't offer operator overloads tend to be rather horrified at this concept the first time they see it (I know I was).
You wouldn't necessarily expect a simple “x+y” expression to be slow, if you're used to programming in C where such expressions typically cause the compiler to emit only one or two machine language instructions.
Operator overloading is no exception, but it as C++ features go it isn't that difficult to use in a safe manner, nor is it intrinsically slow.
And when things do not work, it becomes increasingly difficult to isolate the problem, and in fact, it may be the case that the error is in the interaction of two or more parts of the project that seem to work fine individually.
This allows you to compile and run a program that uses the function, though of course, the results will not be valid, allowing you to see if the other parts of your program work.
A symbolic debugger is a program that allows you to watch the state of your program as it runs and control how your program runs.
Efficient C++ Programming > Returning a Class Object(Site not responding. Last check: 2007-10-02)
Learn the reasons for prefering locality of declaration when using class objects refers, as well as why the initialization of a class object is generally less expensive than its assignment.
By removing the local named object and computing the results directly within the named object, the copy constructor call and one of the destructor calls are eliminated.
An alternative programming idiom is to provide a "computational constructor" that does the work previously done in the actual function, and to return that within the function.
Generic Programming with ConceptGCC(Site not responding. Last check: 2007-10-02)
Generic Programming, which focuses on starting with a concrete (non-templated) algorithm and then slowly introducing template parameters to make it more generic.
The major operations an iterator must be able to perform are (1) increment, (2) dereference, and (3) compare against the end of the sequence.
It may be interesting to step through the program in a debugger, to see how the operators and functions used in the template become calls into the model.
i wanted to overload a + operator to add two objects..i have an error which states "invalid operands `employee *' and `employee *' to binary `operator +'"..
your operator accepts employee objects, you're passing it pointers to such objects.
You might even consider adding an operator that works on pointers so you can do both types of addition.
The following program is the 'guts' of a string class written for an older version of C++.
Because the compiler could not find an operator+ that takes a const String argument, it tried to apply one of the default conversion operators to the expression.
In this case, operator char * fit the bill nicely and was used by the compiler.
A programmer does not usually expect a binary operator to actually alter either one of the arguments; only to return the result.
Posted - 10/7/2004 1:30:00 PM one good way to overload the general arithmetic operators is to compose them out of the arithmetic assigmenet operators e.g.
Also, I recommend you change your operator to be a nonmember function to allow for left-hand conversions prior to addition.
And thus, const void* doesn't have a + operator defined.
It's subscript operator should be overloaded to take that type and return the associated Object (in this case).
A search on comp.lang.c++ (http://groups.google.com/groups?hl=...A5506%40acm.org) revealed that you can't use operator[] on a const map (which is a map that is part of a const object).