contract c { function f1(mapping(uint => uint) calldata) pure external returns (mapping(uint => uint) memory) {} } // ---- // TypeError 4103: (29-59): Types containing (nested) mappings can only be parameters or return variables of internal or library functions. // TypeError 4061: (29-59): Type mapping(uint256 => uint256) is only valid in storage because it contains a (nested) mapping.