Implemented `Length` function

* as its name implies this function returns the length of a given _Cons_ structure
* result type is `Size<Length>` which wraps `std::size_t` to match the `sizeof` operator

3 files changed, 17 insertions, 4 deletions

diff --git a/src/conditional/if.h b/src/conditional/if.h
index 29aa6f0..b9568f6 100644
--- a/src/conditional/if.h
+++ b/src/conditional/if.h
@@ -7,13 +7,13 @@ namespace tav {
 
 template <
 	bool     Condition,
-	typename IfBranch,
-	typename ElseBranch
+	typename TrueBranch,
+	typename FalseBranch
 >
 using If = typename std::conditional<
 	Condition,
-	IfBranch,
-	ElseBranch
+	TrueBranch,
+	FalseBranch
 >::type;
 
 }
diff --git a/src/list/list.h b/src/list/list.h
index edd46e8..f21d0fc 100644
--- a/src/list/list.h
+++ b/src/list/list.h
@@ -27,6 +27,16 @@ using Head = Car<Cons>;
 template <typename Cons>
 using Tail = Cdr<Cons>;
 
+template <typename Cons>
+struct Length {
+	typedef Add<Size<1>, typename Length<Cdr<Cons>>::type> type;
+};
+
+template <>
+struct Length<void> {
+	typedef Size<0> type;
+};
+
 template <
 	typename Primary,
 	typename Secondary
diff --git a/src/type.h b/src/type.h
index 304bff4..74e0650 100644
--- a/src/type.h
+++ b/src/type.h
@@ -8,6 +8,9 @@ namespace tav {
 template <int Value>
 using Int = typename std::integral_constant<int, Value>::type;
 
+template <std::size_t Value>
+using Size = typename std::integral_constant<std::size_t, Value>::type;
+
 template <bool Value>
 using Boolean = typename std::integral_constant<bool, Value>::type;