C + + operator overloading

1#include <iostream>2#include <string.h>3 using namespacestd;4 5 //pretending to write an output class6 classOutput7 {8  Public:9     //operator overload mode oneTenoutput&operator>> (stringb) One     { Acout <<b; -         return* This; -     } the  -     //operator overloading mode two -Friend output&operator>> (output& out,inti) -     { +cout <<"output a integer:"<<i; -         return  out; +     } A  atOutputoperator! (void) -     { -cout <<"hehe!\n"; -         return* This; -     } - }; in  - intMain () to { +Output out; -     stringHello ="Hello, world!\n."; the      out>>Hello; *      out>>"Hello, world!\n."; $      out>>"Hello, world!\n.">>"Good bye!\n";Panax Notoginseng      out= ! out; -  the      out>>23333>>"\ n"; +  Acout <<"Hello World"<<Endl; the     return 0; +}

Directly look at the code, C + + operator overloading has two implementations, one is overloaded into a member of the class function, the other is the overload as a friend function, the member function has the this pointer, so one less parameter.

Attach operator Precedence

Priority Level	operator	Description	Example	Binding Nature
1	() [] - . :: ++ --	The parentheses operator that adjusts the precedence Array Subscript access operator To access a member's operator by pointing to the object's pointer Operator that accesses members through the object itself Scope operator Post increment operator Post-decrement operator	(A + B)/4; ARRAY[4] = 2; Ptr->age = 34; Obj.age = 34; Class::age = 2; for (i = 0; i <; i++) ... for (i = ten; i > 0; i--) ...	From left to right
2	! ~ ++ -- - + * & (type) sizeof	Logical take-back operator bitwise inverse (bitwise complement) Predecessor increment operator Pre-decrement operator unary minus operator Unary take positive operator Dereference operator Fetch address operator Type conversion operators Returns the number of bytes occupied by an object operator	if (!done) ... Flags = ~flags; for (i = 0; i <; ++i) ... for (i = ten; i > 0; i.) ... int i =-1; int i = +1; data = *ptr; Address = &obj; int i = (int) floatnum; int size = sizeof (floatnum);	From right to left
3	->* .*	Operator that accesses a member on a pointer through a pointer to a member Operator that accesses a member on an object by pointing to a pointer to a member	Ptr->*var = 24; Obj.*var = 24;	From left to right
4	* / %	Multiplication operator Division operator Take remainder operator	int i = 2 * 4; float F = 10/3; int rem = 4% 3;	From left to right
5	+ -	Addition operator Subtraction operator	int i = 2 + 3; int i = 5-1;	From left to right
6	<< >>	Bitwise left SHIFT operator Bitwise RIGHT SHIFT operator	int flags = << 1; int flags = >> 1;	From left to right
7	< <= > >=	Less than comparison operators Less than or equal to comparison operators Greater than comparison operator Greater than or equal to comparison operator	if (I < 42) ... if (i <= 42) ... if (i > 42) ... if (i >= 42) ...	From left to right
8	== !=	equals comparison operator Not equal to comparison operator	if (i = = 42) ... if (i! = 42) ...	From left to right
9	&	Bitwise AND operator	Flags = flags & 42;	From left to right
10	^	Bitwise XOR OR operator	Flags = flags ^ 42;	From left to right
11	|	Bitwise OR operator	Flags = Flags | 42;	From left to right
12	&&	Logic and operators	if (Conditiona && conditionb) ...	From left to right
13	||	Logical OR operator	if (Conditiona | | conditionb) ...	From left to right
14	? :	Ternary conditional operator	int i = (a > B)? A:B;	From right to left
15	= += -= *= /= %= &= ^= |= <<= >>=	Assignment operator Compound assignment Operator (addition) Compound assignment operator (subtraction) Compound assignment operator (multiplication) Compound assignment Operator (division) Compound assignment operator (take surplus) Compound assignment operators (bitwise AND) Compound assignment operator (bitwise XOR) Compound assignment operator (bitwise OR) Compound assignment operator (bitwise left shift) Compound assignment operator (bitwise RIGHT SHIFT)	int a = b; A + = 3; B-= 4; A *= 5; A/= 2; A%= 3; Flags &= new_flags; Flags ^= new_flags; Flags |= new_flags; Flags <<= 2; Flags >>= 2;	From right to left
16	,	Comma operator	for (i = 0, j = 0; i <; i++, J + +) ...	From left to right

Operators that cannot be overloaded

Only existing C + + operators can be overloaded in C + +, and users are not allowed to define new operators themselves!

Most of the operators in C + + can be overloaded, except for member access operators. The member pointer access operator . * , scope operator :: , length operator sizeof , and conditional operator ?: c4>;

Reference: http://www.cnblogs.com/wiessharling/p/4179753.html

C + + operator overloading