public static void EmitConvertToType(this ILGenerator ilGenerator, Type typeFrom, Type typeTo, bool isChecked = true)
{
if (ilGenerator == null)
{
throw new ArgumentNullException(nameof(ilGenerator));
}
if (typeFrom == null)
{
throw new ArgumentNullException(nameof(typeFrom));
}
if (typeTo == null)
{
throw new ArgumentNullException(nameof(typeTo));
}
var typeFromInfo = typeFrom.GetTypeInfo();
var typeToInfo = typeTo.GetTypeInfo();
var nnExprType = typeFromInfo.GetNonNullableType();
var nnType = typeToInfo.GetNonNullableType();
if (TypeExtensions.AreEquivalent(typeFromInfo, typeToInfo))
{
return;
}
if (typeFromInfo.IsInterface || // interface cast
typeToInfo.IsInterface ||
typeFrom == typeof(object) || // boxing cast
typeTo == typeof(object) ||
typeFrom == typeof(System.Enum) ||
typeFrom == typeof(System.ValueType) ||
TypeExtensions.IsLegalExplicitVariantDelegateConversion(typeFromInfo, typeToInfo))
{
ilGenerator.EmitCastToType(typeFromInfo, typeToInfo);
}
else if (typeFromInfo.IsNullableType() || typeToInfo.IsNullableType())
{
ilGenerator.EmitNullableConversion(typeFromInfo, typeToInfo, isChecked);
}
else if (!(typeFromInfo.IsConvertible() && typeToInfo.IsConvertible()) // primitive runtime conversion
&&
(nnExprType.GetTypeInfo().IsAssignableFrom(nnType) || // down cast
nnType.GetTypeInfo().IsAssignableFrom(nnExprType))) // up cast
{
ilGenerator.EmitCastToType(typeFromInfo, typeToInfo);
}
else if (typeFromInfo.IsArray && typeToInfo.IsArray)
{
// See DevDiv Bugs #94657.
ilGenerator.EmitCastToType(typeFromInfo, typeToInfo);
}
else
{
ilGenerator.EmitNumericConversion(typeFromInfo, typeToInfo, isChecked);
}
}
