public static BoundConstantExpression FoldConstantUnaryPrefixExpression(
BindContext context,
PrefixUnaryExpressionSyntax syntax,
MethodSymbol unaryOperator,
BoundExpression operand)
{
if (!operand.IsConstant)
{
return(null);
}
if (unaryOperator.IsOperator && unaryOperator.IsExtern)
{
object foldedValue;
object operandValue = operand.ConstantValue.Value;
switch (syntax.OperatorToken.Kind())
{
case SyntaxKind.MinusToken:
foldedValue = DynamicInvoke.UnaryNegate(operandValue);
break;
case SyntaxKind.ExclamationToken:
foldedValue = DynamicInvoke.UnaryNot(operandValue);
break;
case SyntaxKind.TildeToken:
foldedValue = DynamicInvoke.BitwiseNot(operandValue);
break;
default:
return(null);
}
IConstantValue constantValue = (IConstantValue)Activator.CreateInstance(typeof(ConstantValue <>).MakeGenericType(foldedValue.GetType()), foldedValue);
return(new BoundConstantExpression(constantValue, context.GetTypeSymbol(foldedValue.GetType()), syntax));
}
return(null);
}