Specifies that the type is a pointer-like object which can be compared to std::nullptr_t objects. Requirements The type must meet all of the following concept requirements: EqualityComparable DefaultConstructible CopyConstructible CopyAssignable Destructible In addition, a value-initialized object of the type must produce a null value of that type. This null value shall only be equivalent to itself. Default initialization of the type may have an indeterminate value. An object of

A null-terminated wide string is a sequence of valid wide characters, ending with a null character. Functions Character classification Defined in header <cwctype> iswalnum checks if a wide character is alphanumeric (function) iswalpha checks if a wide character is alphabetic (function) iswlower checks if a wide character is lowercase (function) iswupper checks if a wide character is an uppercase character (function) iswdigit checks if a wide character i

This header is part of the numeric library. Functions iota (C++11) fills a range with successive increments of the starting value (function template) accumulate sums up a range of elements (function template) inner_product computes the inner product of two ranges of elements (function template) adjacent_difference computes the differences between adjacent elements in a range (function template) partial_sum computes the partial sum of a range of elements (function te

A null-terminated byte string (NTBS) is a sequence of nonzero bytes followed by a byte with value zero (the terminating null character). Each byte in a byte string encodes one character of some character set. For example, the character array {'\x63', '\x61', '\x74', '\0'} is an NTBS holding the string "cat" in ASCII encoding. Functions Character classification Defined in header <cctype> isalnum checks if a character is alphanumeric (function) isalpha checks if a chara

A null-terminated multibyte string (NTMBS), or "multibyte string", is a sequence of nonzero bytes followed by a byte with value zero (the terminating null character). Each character stored in the string may occupy more than one byte. The encoding used to represent characters in a multibyte character string is locale-specific: it may be UTF-8, GB18030, EUC-JP, Shift-JIS, etc. For example, the char array {'\xe4','\xbd','\xa0','\xe5','\xa5','\xbd','\0'} is an NTMBS holding the string "你好" in UTF-8

Defined in header <cstddef> Defined in header <cstring> Defined in header <cwchar> Defined in header <ctime> Defined in header <cstdio> (until C++11) Defined in header <clocale> (since C++11) Defined in header <cstdlib> (since C++11) #define NULL /*implementation-defined*/ The macro NULL is an implementation-defined null pointer constant, which may be. an integral constant expression rvalue of integer

Usage alternative operators: as an alternative for !

A non-static member function is a function that is declared in a member specification of a class without a static or friend specifier. class S { int mf1(); // non-static member function declaration void mf2() volatile, mf3() &&; // can be cv-qualified and reference-qualified int mf4() const { return data; } // can be defined inline virtual void mf5() final; // can be virtual, can use final/override S() : data(12) {} // constructors are member functions too int da

Usage alternative operators: as an alternative for !=

Specifies whether a function will throw exceptions or not. Syntax noexcept (1) noexcept(expression) (2) 1) Same as noexcept ( true ) 2) If expression evaluates to true, the function is declared to not throw any exceptions. expression - constant expression, contextually convertible to bool Explanation The noexcept-specification (just like dynamic exception specification) can appear as a part of a lambda declarator or a top-level function declarator when declaring f