Programming Stream C11 C++11

Agreed Detail Changes to OOP344/BTP300

C++ Part

• new - add to align with C++11

• • types - specification and qualification

trivial - redefinition of char modified to be the size necessary to store 8-bit coding of UTF-8 and basic execution character set wchar_t, char16_t, char32_t – Unicode support for UTF-16 and UTF-32

trivial - constexpr – function or object constructor is a compile-time constant – qualifier on types other than int enum

trivial - decltype() deduces the type of the expression at compile time

trivial - enum forward declarations admissible as long as the size is specified

using syntax alternative for typedef – using OtherType = ... ;

trivial - thread_local storage duration – variable unique to the thread

• • expressions

trivial - sizeof()works on members of uninstantiated classes

trivial - L' ' and L” “ - prefix for wide character

trivial - codepoint constants defined using \u \U

string literals defined using prefixes u8” ” u” ” and U” ”

trivial - R” “ raw string literal avoids escaping strings manually cf. XML files, scripts, regex

trivial - R can be combined with wide-character literal or Unicode prefixes

• • functions

anonymous (lambda) functions [](int x){ return x + 2; } - return type is implicit as long as all expressions return the same type

alternate trailing-return-type function syntax auto foo(int a, int b) -> decltype(a + b) { return a + b; }

• • encapsulation

constexpr ctor – contains only constant expression

rvalues –modifiable temporaries – T&& – to avoid deep copies on pass/return by value - move constructor T::T(T&&) copies pointer out of rvalue into new temp and sets rvalue pointer to nullptr – move assignment operator T& T::operator=(T&&)

trivial - delegated construction allows default value to be changed without recompilation of application code (e.g. SomeType() : SomeType(42))

trivial - SomeType() = default explicit default

trivial - explicit conversion operators – keyword can be applied here also

trivial - less restrictions on members of a union

• • inheritance

trivial - inherited constructors – using BaseClass::BaseClass

trivial - override identifier of base class virtual function

trivial - final identifier – prevent further overrides

• • polymorphism - fuller generic programming support - templates

trivial - extern template – do not instantiate template in this translation unit

trivial - right angle bracket closes the template where it is reasonable

using syntax for typedef– cf. Template aliases

trivial - variadic templates just extends variadic syntax to templates

trailing return type function syntax auto foo(const T& a, const T& b) -> decltype(a + b) { return a + b; } - return type is unknown for template type T

trivial - static_assert(,) for templates

• • library

initializer lists – extends from POD cases to all classes including std containers - initialization-list constructor – T::T(std::initializer_list<type> list) – initializer list is constant and the data in its members cannot be changed

multi-threading support

• • other features

uniform initialization – uses initializer-list syntax – aggregate initialization, constructor, return list without explicit type

trivial - static_assert(,) – tests assertion at compile-time

C Part

extend existing pre-defined macros to align with C11

pre-defined macros to identify installed features __STDC_*__

trivial - currently covered in C++ part - add to align with C99

inline functions

anonymous structures and unions

• new - add to align with C99 and C++11

bool macro, _Bool data type (C99)

variadic macros

Unicode support – same as C++

static assertions – evaluated later than #if and #error

bounds-checking – list of safe alternative library functions for robust programming

multi-threading support