How to Distinguish between a Lambda and a Function Template at Compile Time

[Meta]

Is this a safe way to distinguish between function literals and 
function literal templates at compile time?

import std.functional;
import std.traits;
template makeFunAlias(alias F)
if (isSomeFunction!(typeof(F)) || is(typeof(F) == void))
{
        static if (is(typeof(F) == void))
        {
                alias makeFunAlias = unaryFun!(F!char);
        }
        else
        {
                alias makeFunAlias = unaryFun!F;
        }       
}

void main()
{
        alias test1 = makeFunAlias!((char c) => c);
        alias test2 = makeFunAlias!(function(char c) => c);
        alias test3 = makeFunAlias!(c => c);
}