This header is part of the containers library. Includes <initializer_list> (C++11) Classes unordered_set (since C++11) collection of unique keys, hashed by keys (class template) unordered_multiset (since C++11) collection of keys, hashed by keys (class template) Functions operator==operator!= compares the values in the unordered_set (function template) std::swap(std::unordered_set) (C++11) specializes the std::swap algorithm (function template) o

Usage unsigned type modifier

Unordered associative containers are Containers that provide fast lookup of objects based on keys. Worst case complexity is linear but on average much faster for most of the operations. Unordered associative containers are parametrized by Key; Hash, a Hash function object which acts as hash function on Key; and Pred, a BinaryPredicate evaluating equivalence between Keys. std::unordered_map and std::unordered_multimap also have a mapped type T associated with the Key. If two Keys are equal accor

Usage declaration of a union type If a function or a variable exists in scope with the name identical to the name of a union type, union can be prepended to the name for disambiguation, resulting in an elaborated type specifier

A uniform random number generator is a function object returning unsigned integer values such that each value in the range of possible results has (ideally) equal probability. Any uniform random number generator may be plugged into any random number distribution. Requirements The type G satisfies UniformRandomNumberGenerator if. Given. T, the type named by G::result_type g, a value of type G The following expressions must be valid and have their specified effects. Expression Return typ

A union is a special class type that can hold only one of its non-static data members at a time. The class specifier for a union declaration is similar to class or struct declaration: union attr class-head-name { member-specification } attr(C++11) - optional sequence of any number of attributes class-head-name - the name of the union that's being defined. Optionally prepended by nested-name-specifier (sequence of names and scope-resolution operators, ending with scope-resol

Requirements An UnformattedInputFunction is a stream input function that performs the following: Constructs an object of type basic_istream::sentry with automatic storage duration and with the noskipws argument set to true, which performs the following if eofbit or badbit are set on the input stream, sets the failbit as well, and if exceptions on failbit are enabled in this input stream's exception mask, throws ios_base::failure. flushes the tie()'d output stream, if applicable Checks

Requirements A UnformattedOutputFunction is a stream output function that performs the following: Constructs an object of type basic_ostream::sentry with automatic storage duration, which performs the following if eofbit or badbit are set on the output stream, sets the failbit as well, and if exceptions on failbit are enabled in this output stream's exception mask, throws ios_base::failure. flushes the tie()'d output stream, if applicable. Checks the status of the sentry by calling se

This header is part of the type support library. Classes Helper Classes integral_constantbool_constant (C++11)(C++17) compile-time constant of specified type with specified value (class template) true_type std::integral_constant<bool, true> false_type std::integral_constant<bool, false> Primary type categories is_void (C++11) checks if a type is void (class template) is_null_pointer (C++14) checks if a type is std::nullptr_t (class templ

Renders the entire program meaningless if certain rules of the language are violated. Explanation The C++ standard precisely defines the observable behavior of every C++ program that does not fall into one of the following classes: ill-formed - the program has syntax errors or diagnosable semantic errors. A conforming C++ compiler is required to issue a diagnostic, even if it defines a language extension that assigns meaning to such code (such as with variable-length arrays). The text of th