static void Test1()
{
//<Snippet19>
DVariant <String, String> dvariant = (String str) => str + " ";
dvariant("test");
//</Snippet19>
}
private void Build(DVariant node, Hints hints, CompilerContext ctx)
{
cw.Type(Dy.Variant);
cw.GetMember(node.Name);
cw.FunPrep(1);
BuildTupleElements(node.Arguments, node.Location, hints, ctx);
AddLinePragma(node.Location);
cw.NewArgs(node.Arguments.Count);
cw.FunArgNm("values");
cw.FunCall(1);
}
public static void Test()
{
int i = 0;
DInvariant <int> dInt = () => i;
DVariant <int> dVariantInt = () => i;
// All of the following statements generate a compiler error
// because type variance in generic parameters is not supported
// for value types, even if generic type parameters are declared variant.
// DInvariant<Object> dObject = dInt;
// DInvariant<long> dLong = dInt;
// DVariant<Object> dVariantObject = dVariantInt;
// DVariant<long> dVariantLong = dVariantInt;
}
public void TestVariance()
{
DInvariant <string> dinString = () => "";
//DInvariant<object> dinObject = dinString;
DCovariant <string> dcoString = () => " ";
DCovariant <object> dcoObject = dcoString;
DContravariant <object> dcontraObject = (a) => Console.WriteLine(a);
DContravariant <string> dcontraString = dcontraObject;
DVariant <object, string> dObjectString = (a) => $"{a} ";
DVariant <object, object> dObjectObject = dObjectString;
DVariant <string, string> dStringString = dObjectString;
DVariant <string, object> dStringObject = dObjectString;
}
