C++ keyword: constexpr (since C++11)

 

C++

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C++ language

General topics
Preprocessor Comments	Keywords Escape sequences
Flow control
Conditional execution statements
if	switch
Iteration statements (loops)
for range-for (C++11)	while do-while
Jump statements
continue - break	goto - return
Functions
Function declaration
Lambda function expression
inline specifier
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noexcept specifier (C++11)
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throw-expression try block	catch handler
Namespaces
Namespace declaration	Namespace aliases
Types
Fundamental types Enumeration types Function types	Class/struct types Union types
Specifiers
const/volatile decltype (C++11) auto (C++11)	constexpr (C++11) consteval (C++20) constinit (C++20)
Storage duration specifiers
Initialization
Default-initialization Value-initialization Zero-initialization Copy-initialization Direct-initialization	Aggregate initialization List-initialization (C++11)   Constant initialization Reference initialization

Expressions
Value categories Order of evaluation	Operators Operator precedence
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Boolean - Integer - Floating-point
Character - String - nullptr (C++11)
User-defined (C++11)
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Attributes (C++11)
Types
typedef declaration
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Implicit conversions static_cast const_cast	Explicit conversions dynamic_cast reinterpret_cast
Memory allocation
new expression	delete expression
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Class declaration Constructors this pointer	Access specifiers friend specifier
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Virtual function override specifier (C++11)   final specifier (C++11)	explicit (C++11) static
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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	History of C++

 

Keywords

alignas (C++11) alignof (C++11) and and_eq asm auto (*) bitand bitor bool break case catch char char8_t (C++20) char16_t (C++11) char32_t (C++11) class compl concept (C++20) const consteval (C++20) constexpr (C++11) constinit (C++20) const_cast continue contract_assert (C++26)   co_await (C++20) co_return (C++20) co_yield (C++20) decltype (C++11) default	delete do double dynamic_cast else enum explicit export extern false float for friend goto if inline int long mutable namespace new noexcept (C++11)   not not_eq nullptr (C++11) operator or or_eq private protected public	register reinterpret_cast requires (C++20) return short signed sizeof (*) static static_assert (C++11) static_cast struct switch template this thread_local (C++11) throw true try typedef typeid typename union unsigned using virtual void volatile wchar_t while xor xor_eq
Identifiers with special meaning
final (C++11) import (C++20) module (C++20)	override (C++11) post (C++26) pre (C++26)	replaceable_if_eligible (C++26) trivially_relocatable_if_eligible (C++26)

 

Usage

• constexpr declaration specifier

constexpr if statement lambda-declarator that explicitly specifies the function call to be a constexpr function

(since C++17)

See also

• if statement: if, else

consteval if statement: consteval

(since C++23)

• switch statement: case, default (as the declaration of the default case label), switch
• goto statement: goto
• continue statement: continue
• break statement: break
• return statement: return, co_return(since C++20)
• do-while loop and while loop: do, while
• for loop and range-based for loop: for