Making a compiled constructor expression with just the Type of the type
c#, delegates, lambda, reflection
Solution
Use the non-generic overload in combination with `MakeGenericType`:
var lamda = Expression.Lambda<Func<????>>(Expression.New(ctor));
Should become:
var funcType = typeof(Func<>).MakeGenericType(type);
var lamda = Expression.Lambda(funcType, Expression.New(ctor));
Problem
I've been playing around, partially reinventing wheels so that I can understand how proper wheels spin round. Consider this generic function for compiling and returning the default constructor of a type. ``` public static Func<TConcrete> Creator<TConcrete>() { // All checking removed for brevity var ctor = typeof(TConcrete).GetConstructor(new Type[0]); var lambda = Expression.Lambda<Func<TConcrete>>(Expression.New(ctor)); return lambda.Compile(); } ``` I believe this will return me a nice typed delegate that I can use to instantiate the passed type. Now consider, I want a function that would do this for a set of different types, how would I go about that? I was thiking along the lines of ... ``` public static IEnumerable<Delegate> Creators(IEnumerable<Type> types) { foreach (var type in types) { var ctor = type.GetConstructor(new Type[0]); var lamda = Expression.Lambda<Func<????>>(Expression.New(ctor)); yield return lambda.Compile(); } } ``` As you can see from the `????` this is where I got stuck. Is there a way to do this or is my approach just flawed?