P0716R0.pdf

Document number P0716R0, dated 2017-06-19, proposes a unified concept definition syntax for C++. The authors, Richard Smith and Andrew Sutton, suggest removing the distinction between function-like and variable-like concept definitions and the "bool" keyword. The proposed syntax is:
template concept identifier = constraint-expression;
This approach aims to simplify concept definitions, avoiding the complexities of variable declaration syntax, and is intended to be equivalent to defining a concept as a 'constexpr bool' variable template with restrictions. The proposal also includes removing concept overloading and changing concept specializations to prvalues, behaving like manifest constants. The Ranges TS will be updated separately to use non-overloaded variable concepts.