Class TwoOperands::Set

A class that represents a pair of operands of the same operation, where the two operands are different.

Example usage:

predicate myBinaryTest(Expr a, Expr b) {
  exists(TwoOperands<BinaryExpr>::Set set |
    set.someOperand().isInteger() and
    set.otherOperand().isConstant()
  )
}

There are two things to be careful about when using this class:

• If the Set is not properly constrained, then the results of someOperand() and otherOperand() may not be different operands. Always bind the Set to be a singular instance, e.g. exists(TwoOperands<BinaryExpr>::Set set | ... ), and never mix getASet calls, e.g. ...::getASet(e).someOperand().... and ...::getASet(e).otherOperand()......
• The Set class extends the operand returned by someOperand(). This perhaps unexpected approach is done to allow the CodeQL engine to perform optimizations by inlining which would not be possible if the Set class was a newtype of all operand pairs, while allowing that someOperand() and otherOperand() to consistent and different.

For an alternative, more minimal API see the set predicate.