Using inherited constructor in Solidity >=0.5.0

Question

I want to use a contract inherit from another contract and use the parent constructor after using another commands in inherited constructor. So I wrote:

pragma solidity ^0.5.10;

contract A {
    constructor(uint x) public {
        //some commands
    }
}
contract B is A {
    contructor(uint x) public {
        //another commands that must be executed first

        //calling A constructor with x parameter:
        A(x);
        //or:
        super.constructor(x); //has error
        //or ???
    }
}

If I use the first solution it assumes that it should cast x variable as A contract. another solutions result error.

If we use A(x) as the B constructor modifier there is no way to run the parent commands after the inherited commands.

    ...
    contructor(uint x) public A(x) {
        //another commands that must be executed first
    }
    ...

finally I was forced to use a secondary function as follows:

pragma solidity ^0.5.10;

contract A {
    constructor(uint x) public {
        p(x);
    }
    function p(uint x) internal {
        //some commands
    }
}
contract B is A {
    contructor(uint x) public {
        //another commands that must be executed first

        //calling A constructor with x parameter:
        A.p(x);
        //or:
        super.p(x);
    }
}

Is there any straight solution, so we don't need to use the secondary function?

Answer 1

Having contract A

pragma solidity ^0.5.0;

contract A {
    uint public a;
    constructor(uint _a) internal {
        a = _a;
    }
}

...

you can either pass a constant argument with this syntax

...

contract B is A(1) {
    constructor() public {}
}

or you can pass a variable with this syntax.

...

contract B is A {
    constructor(uint _y) A(_y * _y) public {}
}