From c93aa4c90df7a814a076ebc8d92cc94d4fa96910 Mon Sep 17 00:00:00 2001
From: Mathias Agopian <mathias@google.com>
Date: Fri, 15 Mar 2024 13:59:56 -0700
Subject: [PATCH] minor libutils improvements

---
 libs/utils/include/utils/FixedCapacityVector.h | 10 ++++++++++
 libs/utils/include/utils/bitset.h              | 12 +++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/libs/utils/include/utils/FixedCapacityVector.h b/libs/utils/include/utils/FixedCapacityVector.h
index f399012485..d734117a35 100644
--- a/libs/utils/include/utils/FixedCapacityVector.h
+++ b/libs/utils/include/utils/FixedCapacityVector.h
@@ -299,6 +299,16 @@ public:
         }
     }
 
+    UTILS_NOINLINE
+    void shrink_to_fit() {
+        if (size() < capacity()) {
+            FixedCapacityVector t(construct_with_capacity, size(), allocator());
+            t.mSize = size();
+            std::uninitialized_move(begin(), end(), t.begin());
+            this->swap(t);
+        }
+    }
+
 private:
     enum construct_with_capacity_tag{ construct_with_capacity };
 
diff --git a/libs/utils/include/utils/bitset.h b/libs/utils/include/utils/bitset.h
index 281e5dfcf2..8844fdb80a 100644
--- a/libs/utils/include/utils/bitset.h
+++ b/libs/utils/include/utils/bitset.h
@@ -60,6 +60,11 @@ public:
         std::fill(std::begin(storage), std::end(storage), 0);
     }
 
+    template<typename U, typename = typename std::enable_if_t<N == 1, U>>
+    explicit bitset(U value) noexcept {
+        storage[0] = value;
+    }
+
     T getBitsAt(size_t n) const noexcept {
         assert_invariant(n<N);
         return storage[n];
@@ -94,6 +99,8 @@ public:
 
     size_t size() const noexcept { return N * BITS_PER_WORD; }
 
+    bool empty() const noexcept { return none(); }
+
     bool test(size_t bit) const noexcept { return operator[](bit); }
 
     void set(size_t b) noexcept {
@@ -117,11 +124,14 @@ public:
         storage[b / BITS_PER_WORD] ^= T(1) << (b % BITS_PER_WORD);
     }
 
-
     void reset() noexcept {
         std::fill(std::begin(storage), std::end(storage), 0);
     }
 
+    void clear() noexcept {
+        reset();
+    }
+
     bool operator[](size_t b) const noexcept {
         assert_invariant(b / BITS_PER_WORD < N);
         return bool(storage[b / BITS_PER_WORD] & (T(1) << (b % BITS_PER_WORD)));