Cannot convert from 'System.Collections.IList' to 'System.Collections.Generic.IEnumer-CodePudding

Using C# 10 I am trying to convert an IEnumerable<String>? to an IEnumerable<T>:

IEnumerable<String>? inputs = getValues();

if (inputs is null)
  return false;

Type type = typeof(List<>).MakeGenericType(typeof(T));

IList? outputs = (IList?)Activator.CreateInstance(type);

TypeConverter converter = TypeDescriptor.GetConverter(typeof(T));

if (converter is null || outputs is null || !converter.CanConvertFrom(typeof(String)))
  return false;

foreach (String input in inputs) {
  if (converter.IsValid(input)) 
    outputs.Add(converter.ConvertFromString(input));
}

var texpression = new TExpression<T>(outputs);

I am getting an error on last line even if I use outputs.ToList():

Cannot convert from 'System.Collections.IList' to 'System.Collections.Generic.IEnumerable<T>'

The TExpression constructor is:

public TExpression(IEnumerable<T> values) { 
  Values = values;
}

I tried to change the types of my conversion code but I always end with an error somewhere.

How can I fix this so I can use the constructor without changing the constructor?

Update

Using the following:

IList<T> outputs = (IList<T>)Activator.CreateInstance(type);
...
foreach (string input in inputs) {
  if (converter.IsValid(input)) 
    outputs.Add((T)converter.ConvertFromString(input));
}

I get the warning (I am using <Nullable>enable</Nullable>):

Converting null literal or possible null value to non-nullable type.

T can be a nullable type (Int32?) or a non nullable type (Int32).

I could change the code line to:

T? output = (T?)converter.ConvertFromString(input);

This fixes the warning but is it correct?

What if T is a non nullable type?

CodePudding user response：

Since you actually now the type of collection you can use it:

IList<T> outputs = (IList<T>)Activator.CreateInstance(type);
...
foreach (string input in inputs) {
    if (converter.IsValid(input)) 
        outputs.Add((T)converter.ConvertFromString(input)); // here also
}