solidity/test/libsolidity/syntaxTests/constructor/constructor_visibility_old.sol

// The constructor of a base class should not be visible in the derived class
contract A { function A(string s) public { } }
contract B is A {
  function f() pure public {
    A x = A(0); // convert from address
    string memory y = "ab";
    A(y); // call as a function is invalid
    x;
  }
}
// ----
// Warning: (91-122): Defining constructors as functions with the same name as the contract is deprecated. Use "constructor(...) { ... }" instead.
// TypeError: (244-248): Explicit type conversion not allowed from "string memory" to "contract A".