Reimplemented `Find` in terms of `ListIndex`

* `ListIndex` already implements the necessary partial template specializations for finding elements matching a predicate
* reimplemented `Cond` using `detail::find_variadic` as `Find` depends on `Apply` which in turn depends on `Cond`
** it is useful if core functionality such as the branched conditional `Cond` do not require higher order functionality such as `Find`
*** otherwise one can not use core functionality in the implementation of higher order functionality
* introduced `utility::predicate_guard` helper template
** checks a given value using a predicate and only forwards the value to the guarded function if this check is successful
** if check is unsuccessful it returns a surrogate value simmilar to `utility::predicate_assurance`

1 files changed, 4 insertions, 10 deletions

diff --git a/src/conditional/cond.h b/src/conditional/cond.h
index eeb31b6..8a34f79 100644
--- a/src/conditional/cond.h
+++ b/src/conditional/cond.h
@@ -1,10 +1,7 @@
 #ifndef TYPEASVALUE_SRC_CONDITIONAL_COND_H_
 #define TYPEASVALUE_SRC_CONDITIONAL_COND_H_
 
-#include <type_traits>
-
-#include "list/list.h"
-#include "list/operation/higher/find.h"
+#include "list/detail/find_variadic.h"
 
 namespace tav {
 
@@ -16,12 +13,9 @@ using cond_predicate = IsTrue<Car<Pair>>;
 }
 
 template <typename... Branches>
-using Cond = Cdr<
-	Find<
-		detail::cond_predicate,
-		List<Branches...>
-	>
->;
+using Cond = Cdr<Eval<
+	detail::find_variadic<detail::cond_predicate, Branches...>
+>>;
 
 }