Spring4D TMultiMap overloaded constructor not seen by compiler (Error E2250) - delphi

Question

I'm struggling with Spring4D (1.2.2) TMultiMap generic class. I want to call an overloaded constructor and the compiler complain:
"E2250 There is no overloaded version of 'Create' that can be called with these arguments"
The argument is the correct type according to the Spring4D source code.
I devised a small do-nothing program reproducing the error:
program Spring4DMultiMapTest;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.SysUtils,
Generics.Collections,
Spring.Tests.Interception.Types,
Spring.Collections.MultiMaps,
Spring.Collections;
type
TMyKey = TPair<Double, Integer>;
TMyKeyEqualityComparer = class(TInterfacedObject, IEqualityComparer<TMyKey>)
function Equals(const Left, Right: TMyKey): Boolean; reintroduce;
function GetHashCode(const Value: TMyKey): Integer; reintroduce;
end;
function TMyKeyEqualityComparer.Equals(const Left, Right: TMyKey): Boolean;
begin
if Left.Key < (Right.Key - 1E-9) then
Result := TRUE
else if Left.Key > (Right.Key + 1E-9) then
Result := FALSE
else if Left.Value < Right.Value then
Result := TRUE
else
Result := FALSE;
end;
function TMyKeyEqualityComparer.GetHashCode(const Value: TMyKey): Integer;
begin
Result := Value.Value + Round(Value.Key * 1E6);
end;
var
Events : IMultiMap<TMyKey, Integer>;
KeyComparer : IEqualityComparer<TMyKey>;
begin
KeyComparer := TMyKeyEqualityComparer.Create;
// Next line triggers error: "E2250 There is no overloaded version of 'Create' that can be called with these arguments"
Events := TMultiMap<TMyKey, Integer>.Create(KeyComparer);
end.
In Spring4D source code, I find the following declaration:
TMultiMap<TKey, TValue> = class(TMultiMapBase<TKey, TValue>)
and also the TMultiMap acestor is declared:
TMultiMapBase<TKey, TValue> = class abstract(TMapBase<TKey, TValue>,
IMultiMap<TKey, TValue>, IReadOnlyMultiMap<TKey, TValue>)
and has this constructor:
constructor Create(const keyComparer: IEqualityComparer<TKey>); overload;
This is the constructor I want to call. As far as I understand, my argument KeyComparer has the correct type. But obviously the compiler doesn't agree :-(
How to fix this code?

Answer 1

You use different IEqualityComparer<T> types.
The IEqualityComparer<T> in your example comes from Spring.Tests.Interception.Types.pas. The one used in TMultiMap<TKey, TValue>.Create constructor is defined in System.Generics.Defaults.pas.
If you change your uses part to
uses
System.SysUtils,
Generics.Collections,
// Spring.Tests.Interception.Types,
Generics.Defaults,
Spring.Collections.MultiMaps,
Spring.Collections;
your example will compile.
Tested with Delphi 10.3 U3 and Spring4D 1.2.2