Dylan Hicks' IsIsogram()

[Dylan_Hicks]

auto FBullCowGame::IsIsogram(FString Word) const -> bool
{
    TSet<char> LettersSeen;

    for (auto Letter : Word)
    {
        Letter = std::tolower(Letter);

        auto Search = LettersSeen.find(Letter);

        if (Search != std::end(LettersSeen))
        {
            return false;
        }
        else
        {
            LettersSeen.insert(Letter);
        }
    }

    return true;
}