public static IEnumerable <T> AddIfNotNull <T>(this IEnumerable <T> source, T value)
{
return(Colls.AddIf(source, value, v => v is not null));
}
public static IEnumerable <T> AddIf <T>(this IEnumerable <T> source, T value, Func <T, bool> condition)
{
return(Colls.AddIf(source, value, condition));
}
public static IEnumerable <T> AddIfNotExist <T>(this IEnumerable <T> source, T value, Func <T, bool> existFunc = null)
{
Func <T, bool> condition = t => !source.Contains(t);
return(Colls.AddIf(source, value, v => existFunc?.Invoke(v) ?? condition(v)));
}
public static IEnumerable <T> AddIf <T>(this IEnumerable <T> source, T value, bool flag)
{
return(Colls.AddIf(source, value, flag));
}