1 type A where 'a: 'b + 'c = u8; // OK
2 type A where 'a: 'b, = u8; // OK
3 type A where 'a: = u8; // OK
4 type A where 'a:, = u8; // OK
5 type A where 'a: 'b + 'c = u8; // OK
6 type A where = u8; // OK
7 type A where 'a: 'b + = u8; // OK
8 type A where , = u8; //~ ERROR expected one of `;`, `=`, `where`, lifetime, or type, found `,`