From 8e6219ef86c9467af71db691116cd819ca45ec07 Mon Sep 17 00:00:00 2001
From: Suyeol Jeon <devxoul@gmail.com>
Date: Mon, 14 Sep 2015 22:31:55 +0900
Subject: [PATCH] Add availability check for iOS 8 attributes.

---
 Source/ConstraintAttributes.swift | 54 ++++++++++++++++---------------
 1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/Source/ConstraintAttributes.swift b/Source/ConstraintAttributes.swift
index 06b3dec..e19b18b 100644
--- a/Source/ConstraintAttributes.swift
+++ b/Source/ConstraintAttributes.swift
@@ -125,32 +125,34 @@ internal struct ConstraintAttributes: OptionSetType, BooleanType {
             attrs.append(.Baseline)
         }
         #if os(iOS)
-        if (self.contains(ConstraintAttributes.FirstBaseline)) {
-            attrs.append(.FirstBaseline)
-        }
-        if (self.contains(ConstraintAttributes.LeftMargin)) {
-            attrs.append(.LeftMargin)
-        }
-        if (self.contains(ConstraintAttributes.RightMargin)) {
-            attrs.append(.RightMargin)
-        }
-        if (self.contains(ConstraintAttributes.TopMargin)) {
-            attrs.append(.TopMargin)
-        }
-        if (self.contains(ConstraintAttributes.BottomMargin)) {
-            attrs.append(.BottomMargin)
-        }
-        if (self.contains(ConstraintAttributes.LeadingMargin)) {
-            attrs.append(.LeadingMargin)
-        }
-        if (self.contains(ConstraintAttributes.TrailingMargin)) {
-            attrs.append(.TrailingMargin)
-        }
-        if (self.contains(ConstraintAttributes.CenterXWithinMargins)) {
-            attrs.append(.CenterXWithinMargins)
-        }
-        if (self.contains(ConstraintAttributes.CenterYWithinMargins)) {
-            attrs.append(.CenterYWithinMargins)
+        if #available(iOS 8.0, *) {
+            if (self.contains(ConstraintAttributes.FirstBaseline)) {
+                attrs.append(.FirstBaseline)
+            }
+            if (self.contains(ConstraintAttributes.LeftMargin)) {
+                attrs.append(.LeftMargin)
+            }
+            if (self.contains(ConstraintAttributes.RightMargin)) {
+                attrs.append(.RightMargin)
+            }
+            if (self.contains(ConstraintAttributes.TopMargin)) {
+                attrs.append(.TopMargin)
+            }
+            if (self.contains(ConstraintAttributes.BottomMargin)) {
+                attrs.append(.BottomMargin)
+            }
+            if (self.contains(ConstraintAttributes.LeadingMargin)) {
+                attrs.append(.LeadingMargin)
+            }
+            if (self.contains(ConstraintAttributes.TrailingMargin)) {
+                attrs.append(.TrailingMargin)
+            }
+            if (self.contains(ConstraintAttributes.CenterXWithinMargins)) {
+                attrs.append(.CenterXWithinMargins)
+            }
+            if (self.contains(ConstraintAttributes.CenterYWithinMargins)) {
+                attrs.append(.CenterYWithinMargins)
+            }
         }
         #endif
         return attrs