False compiler DeclarationError: Modifier already used for this function

[elenadimitrova]

Solidity compiler throws an error

DeclarationError: Modifier already used for this function.

when a function uses modifier twice with different parameters, e.g.

modifier nonZeroAddress(address x) {
    require(x != 0);
    _;
  }

function X(address a, address b) 
nonZeroAddress(a)
nonZeroAddress(b)
{ ... }

[axic]

This was introduced in #2460.

[onbjerg]

Why was the version not bumped to reflect #2460, which is a breaking change?

There are legitimate use cases to use the same modifier twice on the same function.

[chriseth]

Ah, I see. To be honest, I did not consider multiple uses of the same modifier, but seeing your example, that was obviously a stupid assumption :-)

[chriseth]

Will work on this.

[onbjerg]

No worries, thanks for the swift response 😄 Happy hacking!