protected override BoundExpression GenerateCall(SyntheticBoundNodeFactory f, BoundExpression receiver, ImmutableArray <BoundExpression> arguments, ImmutableArray <RefKind> refKinds, DiagnosticBag diagnostics)
{
// For user-defined operators, the normal shim call approach works
// fine. However, we also want to permit shim calls into types
// with builtin operators, for which we need to do an actual
// lookup as to which operator we're defining, and a quick
// jump into part of the operator overload resolution code to see
// if we're actually in one of those types.
//
// This may be incomplete, but is probably(??) sound.
// TODO(@MattWindsor91): consider refkinds?
if (ImplementingMethod.OriginalDefinition is SourceUserDefinedOperatorSymbol op)
{
Debug.Assert(receiver.Kind == BoundKind.TypeExpression,
"receiver of an operator should always be a type");
var rectype = (BoundTypeExpression)receiver;
var opdecl = op.GetSyntax();
Debug.Assert(opdecl != null, "should have operator syntax here");
var opsyn = opdecl.OperatorToken;
var opkind = opsyn.Kind();
var binder = DeclaringCompilation.GetBinder(ImplementingMethod.GetNonNullSyntaxNode()).WithAdditionalFlagsAndContainingMemberOrLambda(BinderFlags.InShim, this);
var ovr = new OverloadResolution(binder);
var ignore = new HashSet <DiagnosticInfo>();
if (arguments.Length == 1)
{
(var usuccess, var ukind) = TryGetUnaryOperatorKind(opsyn.Kind());
if (usuccess)
{
var result = UnaryOperatorOverloadResolutionResult.GetInstance();
ovr.UnaryOperatorOverloadResolution(ukind, arguments[0], result, ref ignore);
if (result.SingleValid())
{
var bsig = result.Best.Signature;
if (bsig.Method == null)
{
return(f.Unary(bsig.Kind, bsig.ReturnType, arguments[0]));
}
}
}
}
else if (arguments.Length == 2)
{
(var bsuccess, var bkind) = TryGetBinaryOperatorKind(opsyn.Kind());
if (bsuccess)
{
var result = BinaryOperatorOverloadResolutionResult.GetInstance();
ovr.BinaryOperatorOverloadResolution(bkind, arguments[0], arguments[1], result, ref ignore);
if (result.SingleValid())
{
var bsig = result.Best.Signature;
if (bsig.Method == null)
{
return(f.Binary(bsig.Kind, bsig.ReturnType, arguments[0], arguments[1]));
}
}
}
}
}
return(base.GenerateCall(f, receiver, arguments, refKinds, diagnostics));
}