ftl::Flags: Offer set and clear APIs for convenience and readability

Bug: None
Test: None
Change-Id: Idbe075dd919fd71bdcb7b1fb4a182c44d243b378
diff --git a/include/ftl/Flags.h b/include/ftl/Flags.h
index 932af2d..708eaf5 100644
--- a/include/ftl/Flags.h
+++ b/include/ftl/Flags.h
@@ -120,10 +120,10 @@
     }
 
     /* Tests whether any of the given flags are set */
-    bool any(Flags<F> f) { return (mFlags & f.mFlags) != 0; }
+    bool any(Flags<F> f) const { return (mFlags & f.mFlags) != 0; }
 
     /* Tests whether all of the given flags are set */
-    bool all(Flags<F> f) { return (mFlags & f.mFlags) == f.mFlags; }
+    bool all(Flags<F> f) const { return (mFlags & f.mFlags) == f.mFlags; }
 
     Flags<F> operator|(Flags<F> rhs) const { return static_cast<F>(mFlags | rhs.mFlags); }
     Flags<F>& operator|=(Flags<F> rhs) {
@@ -153,6 +153,10 @@
         return *this;
     }
 
+    inline Flags<F>& clear(Flags<F> f = static_cast<F>(~static_cast<U>(0))) {
+        return *this &= ~f;
+    }
+
     Iterator begin() const { return Iterator(*this); }
 
     Iterator end() const { return Iterator(); }