C++14 is intended to be a small extension over C++11, featuring mainly bug fixes and small improvements.
* Function return type deduction
* Alternate type deduction on declaration
decltype for reference or non-reference type
* Relaxed constexpr restrictions
C++11 constexpr functions could only contain a single expression that is returned (as well as static_asserts and a small number of other declarations)
C++14 will relax these restrictions.
* Variable templates
In prior versions of C++, only functions, classes or type aliases could be templated. C++14 now allows the creation of variables that are templated.
* Aggregate member initialization
* Binary literals
Numeric literals in C++14 can be specified in binary form.
* Digit separators
* Generic lambdas
In C++11, lambda function parameters need to be declared with concrete types. C++14 relaxes this requirement, allowing lambda function parameters to be declared with the auto type specifier.
* Lambda capture expressions
* The attribute [[deprecated]]
