Alternative operator representations

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

C++ language

General topics
Preprocessor Comments Keywords	ASCII chart Escape sequences History of C++
Flow control
Conditional execution statements
if statement	switch statement
Iteration statements
for loop range-for loop (C++11)	while loop do-while loop
Jump statements
continue statement break statement	goto statement return statement
Functions
function declaration
lambda function declaration
function template
inline specifier
exception specifications (deprecated)
noexcept specifier (C++11)
Exceptions
throw expression	try-catch block
Namespaces
namespace declaration	namespace aliases
Types
fundamental types compound types enumeration types	union types function types
decltype specifier (C++11)
Specifiers
cv specifiers
storage duration specifiers
constexpr specifier (C++11)
auto specifier (C++11)
alignas specifier (C++11)
Initialization
default initialization value initialization zero initialization copy initialization direct initialization	aggregate initialization list initialization (C++11) constant initialization reference initialization

Literals
integer literals character literals floating-point literals string literals	boolean literals nullptr (C++11) user-defined (C++11)
Expressions
value categories order of evaluation	operators operator precedence
alternative representations
Utilities
Types
typedef declaration
type alias declaration (C++11)
attributes (C++11)
Casts
implicit conversions
const_cast conversion
static_cast conversion
dynamic_cast conversion
reinterpret_cast conversion
C-style and functional cast
Memory allocation
new expression	delete expression
Classes
class declaration this pointer access specifiers	friend specifier initializer lists
Class-specific function properties
virtual function override specifier (C++11) final specifier (C++11)	explicit (C++11) static
Special member functions
default constructor copy constructor move constructor (C++11)	copy assignment move assignment (C++11) destructor
Templates
class template
function template
template specialization
parameter packs (C++11)
Miscellaneous
Inline assembly

 

C++ (and C) source code may be written in any non-ASCII 7-bit character set that includes the ISO 646:1983 invariant character set. However, several C++ operators and punctuators require characters that are outside of the ISO 646 codeset: {, }, [, ], #, \, ^, |, ~. To be able to use character encodings where some or all of these symbols do not exist (such as the German DIN 66003), C++ defines two kinds of alternatives: additional keywords that correspond to the operators that use these characters and special combinations of two or three ISO 646 compatible characters that are interpreted as if they were a single non-ISO 646 character.

Alternative keywords

There are alternative spellings for several operators defined as keywords in the C++ standard.

Primary	Alternative
&&	and
&=	and_eq
&	bitand
|	bitor
~	compl
!	not
!=	not_eq
||	or
|=	or_eq
^	xor
^=	xor_eq

Compatibility with C

The same words are defined in the C programming language in the include file <iso646.h> as macros. Because in C++ these are language keywords, the C++ version of <iso646.h>, as well as <ciso646>, does not define anything.

Digraphs and trigraphs

The following combinations of two and three characters (digraphs and trigraphs) are valid substitutions for their respective primary characters:

Primary	Digraph	Trigraph
{	<%	??<
}	%>	??>
[	<:	??(
]	:>	??)
#	%:	??=
\		??/
^		??'
|		??!
~		??-

Note that trigraphs (but not digraphs) are parsed before comments and string literals are recognized, so a comment such as // Will the next line be executed?????/ will effectively comment out the following line, and the string literal such as "What's going on??!" is parsed as "What's going on|".

Keywords

and, and_eq, bitand, bitor, compl, not, not_eq, or, or_eq, xor, xor_eq

Example

The following example demonstrates the use of several alternative keywords:

run this code

%:include <iostream>
 
int main(int argc, char *argv<::>) 
<%
    if (argc > 1 and argv<:1:> not_eq '\0') <%
        std::cout << "Hello " << argv<:1:> << '\n';
    %>
%>