3581 ///     template arguments. A requirement is one that can be checked by name
3585 ///         'requires' requirement-parameter-list[opt] requirement-body
3587 ///     requirement-parameter-list:
3590 ///     requirement-body:
3591 ///         '{' requirement-seq '}'
3593 ///     requirement-seq:
3594 ///         requirement
3595 ///         requirement-seq requirement
3597 ///     requirement:
3598 ///         simple-requirement
3599 ///         type-requirement
3600 ///         compound-requirement
3601 ///         nested-requirement
3609     // requirement parameter list is present.  in ParseRequiresExpression()
3632   // Start of requirement list  in ParseRequiresExpression()
3633   llvm::SmallVector<concepts::Requirement *, 2> Requirements;  in ParseRequiresExpression()
3636   //   Expressions appearing within a requirement-body are unevaluated operands.  in ParseRequiresExpression()
3650     // requirement-body:  in ParseRequiresExpression()
3651     //   { requirement-seq }  in ParseRequiresExpression()
3652     // requirement-seq:  in ParseRequiresExpression()
3653     //   requirement  in ParseRequiresExpression()
3654     //   requirement-seq requirement  in ParseRequiresExpression()
3661         // Compound requirement  in ParseRequiresExpression()
3663         //     compound-requirement:  in ParseRequiresExpression()
3665         //             return-type-requirement[opt] ';'  in ParseRequiresExpression()
3666         //     return-type-requirement:  in ParseRequiresExpression()
3682         concepts::Requirement *Req = nullptr;  in ParseRequiresExpression()
3762                   //                    simple-requirement.  in ParseRequiresExpression()
3770             // Nested requirement  in ParseRequiresExpression()
3772             //     nested-requirement:  in ParseRequiresExpression()
3793           // This might be 'typename T::value_type;' (a type requirement) or  in ParseRequiresExpression()
3794           // 'typename T::value_type{};' (a simple requirement).  in ParseRequiresExpression()
3836         // Simple requirement  in ParseRequiresExpression()
3838         //     simple-requirement:  in ParseRequiresExpression()
3856         // User may have tried to put some compound requirement stuff here  in ParseRequiresExpression()