C++ Language Reference

C++ Language Reference

C++ keywords, core type-system vocabulary, declarations, object model terms, and modern language features.

How to use this reference page

Use reference pages to confirm names, categories, nearby facilities, and the constraints that matter before writing or reviewing code.

Scan the top of the page first to identify the primary types, functions, or algorithm families involved.
Use the nearby-page links when your question is really about a companion header, related algorithm family, or broader subsystem.
Validate tricky behavior with a small compileable example before relying on memory for details like invalidation, ordering, allocation, or lifetime rules.

C++ Language Reference

C++ keywords

Control flow and exceptions

if, else, switch, case, default
for, while, do, break, continue, goto, return
try, catch, throw

Types, declarations, and object model

class, struct, union, enum, typename, typedef, using
template, concept, requires
namespace, inline, explicit, friend, virtual, override, final
public, protected, private
mutable, constexpr, consteval, constinit, const, volatile
static, thread_local, extern, register

Casts and dynamic facilities

static_cast, dynamic_cast, const_cast, reinterpret_cast
new, delete, typeid, decltype, sizeof, alignof, noexcept

Function and coroutine vocabulary

auto, operator, this, nullptr
co_await, co_yield, co_return

Modules and alternative tokens

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

Boolean and literals

true, false, char8_t, char16_t, char32_t, wchar_t

Fundamental and core vocabulary types

Fundamental types

bool
character families: char, signed char, unsigned char, wchar_t, char8_t, char16_t, char32_t
integers: short, int, long, long long and unsigned forms
floating point: float, double, long double
void, std::nullptr_t

Value categories and references

lvalue
xvalue
prvalue
glvalue
lvalue reference: T&
rvalue reference: T&&

Storage duration and lifetime terms

automatic storage duration
static storage duration
thread storage duration
dynamic storage duration
lifetime, scope, linkage, initialization, destruction

Operators and punctuators

Common operator groups

arithmetic, comparison, logical, bitwise, assignment, increment/decrement
member access: ., ->, .*, ->*
call and indexing: (), []
conditional: ?:
scope resolution: ::
fold expressions and pack expansion in templates

Operator overloading targets

arithmetic and comparison operators
stream insertion/extraction
function call and subscript
allocation/deallocation operators
spaceship operator <=>

For a denser operator-by-operator summary, including precedence-oriented groupings and token families, see Operators and punctuators.

High-value modern C++ language features

concepts and requires-clauses
class template argument deduction
structured bindings
designated initializers for aggregates
if constexpr
ranges-friendly APIs via concepts and views
modules
coroutines
defaulted comparison operators
constexpr and consteval computation

Class and template terms you should know

special member functions
rule of zero, rule of five
copy elision
overload resolution
template instantiation
specialization and partial specialization
substitution failure and constraints
argument-dependent lookup
one-definition rule

Practical lookup checklist

Is this runtime polymorphism, compile-time polymorphism, or a value-type design?
Does the type own resources or merely observe them?
Is the operation constrained by concepts, overloads, or implicit conversions?

Adjacent reference pages

Example in practice

struct Point {
    int x{};
    int y{};
};

int main() {
    Point p{3, 4};
    return p.x < p.y;
}