diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 3172fbffb6..5978861a69 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -7,6 +7,7 @@ A new header is inserted each time a *tag* is created.
 
 - gltfio: fix morphing for un-packed accessors
 - engine: disable user scissor while rendering the Shadow Maps (#5607)
+- utils: remove `std::hash<T>` definitions for `libutils` types. Use `T::Hasher` explicitly instead. [⚠️ **API Change**]
 
 ## v1.23.1
 
diff --git a/filament/backend/include/private/backend/Driver.h b/filament/backend/include/private/backend/Driver.h
index 58f543ee8a..ab62179c60 100644
--- a/filament/backend/include/private/backend/Driver.h
+++ b/filament/backend/include/private/backend/Driver.h
@@ -26,6 +26,8 @@
 
 #include <utils/compiler.h>
 
+#include <functional>
+
 #include <stdint.h>
 
 // Command debugging off. debugging virtuals are not called.
diff --git a/filament/backend/include/private/backend/SamplerGroup.h b/filament/backend/include/private/backend/SamplerGroup.h
index f48952235f..7e4ebbd2af 100644
--- a/filament/backend/include/private/backend/SamplerGroup.h
+++ b/filament/backend/include/private/backend/SamplerGroup.h
@@ -17,17 +17,18 @@
 #ifndef TNT_FILAMENT_BACKEND_PRIVATE_SAMPLERGROUP_H
 #define TNT_FILAMENT_BACKEND_PRIVATE_SAMPLERGROUP_H
 
-#include <array>
-#include <stddef.h>
-
 #include <utils/compiler.h>
 #include <utils/bitset.h>
 
 #include <backend/DriverEnums.h>
 #include <backend/Handle.h>
 
-namespace filament {
-namespace backend {
+#include <array>
+#include <memory>
+
+#include <stddef.h>
+
+namespace filament::backend {
 
 class SamplerGroup {
 public:
@@ -151,7 +152,6 @@ private:
     mutable utils::bitset32 mDirty;
 };
 
-} // namespace backend
-} // namespace filament
+} // namespace filament::backend
 
 #endif // TNT_FILAMENT_BACKEND_PRIVATE_SAMPLERGROUP_H
diff --git a/filament/src/PostProcessManager.h b/filament/src/PostProcessManager.h
index be31ee191e..e0705178e1 100644
--- a/filament/src/PostProcessManager.h
+++ b/filament/src/PostProcessManager.h
@@ -316,7 +316,12 @@ private:
         mutable bool mHasMaterial{};
     };
 
-    tsl::robin_map<utils::StaticString, PostProcessMaterial> mMaterialRegistry;
+    using MaterialRegistryMap = tsl::robin_map<
+            utils::StaticString,
+            PostProcessMaterial,
+            utils::StaticString::Hasher>;
+
+    MaterialRegistryMap mMaterialRegistry;
 
     void registerPostProcessMaterial(utils::StaticString name, uint8_t const* data, int size);
     PostProcessMaterial& getPostProcessMaterial(utils::StaticString name) noexcept;
diff --git a/filament/src/details/DebugRegistry.h b/filament/src/details/DebugRegistry.h
index 017e6e4fb5..5207629511 100644
--- a/filament/src/details/DebugRegistry.h
+++ b/filament/src/details/DebugRegistry.h
@@ -72,8 +72,8 @@ private:
     bool hasProperty(const char* name) const noexcept;
     void* getPropertyAddress(const char* name) noexcept;
     DataSource getDataSource(const char* name) const noexcept;
-    std::unordered_map<utils::StaticString, void*> mPropertyMap;
-    std::unordered_map<utils::StaticString, DataSource> mDataSourceMap;
+    std::unordered_map<utils::StaticString, void*, utils::StaticString::Hasher> mPropertyMap;
+    std::unordered_map<utils::StaticString, DataSource, utils::StaticString::Hasher> mDataSourceMap;
 };
 
 FILAMENT_UPCAST(DebugRegistry)
diff --git a/filament/src/details/Scene.h b/filament/src/details/Scene.h
index bd79755b2a..b578d32fcb 100644
--- a/filament/src/details/Scene.h
+++ b/filament/src/details/Scene.h
@@ -208,7 +208,7 @@ private:
      * (a vector<> could work, but removes would be O(n)). robin_set<> iterates almost as
      * nicely as vector<>, which is a good compromise.
      */
-    tsl::robin_set<utils::Entity> mEntities;
+    tsl::robin_set<utils::Entity, utils::Entity::Hasher> mEntities;
 
 
     /*
diff --git a/filament/src/fg/Blackboard.h b/filament/src/fg/Blackboard.h
index 0912c0f893..808ba08c40 100644
--- a/filament/src/fg/Blackboard.h
+++ b/filament/src/fg/Blackboard.h
@@ -26,7 +26,10 @@
 namespace filament {
 
 class Blackboard {
-    using Container = std::unordered_map<utils::StaticString, FrameGraphHandle>;
+    using Container = std::unordered_map<
+            utils::StaticString,
+            FrameGraphHandle,
+            utils::StaticString::Hasher>;
 
 public:
     Blackboard() noexcept;
diff --git a/libs/filameshio/include/filameshio/MeshReader.h b/libs/filameshio/include/filameshio/MeshReader.h
index f9da44bdec..2253379120 100644
--- a/libs/filameshio/include/filameshio/MeshReader.h
+++ b/libs/filameshio/include/filameshio/MeshReader.h
@@ -63,7 +63,7 @@ public:
 
          void unregisterAll();
 
-         std::size_t numRegistered() const noexcept;
+         size_t numRegistered() const noexcept;
 
          void getRegisteredMaterials(filament::MaterialInstance** materialList,
                  utils::CString* materialNameList) const;
diff --git a/libs/gltfio/src/DependencyGraph.h b/libs/gltfio/src/DependencyGraph.h
index 9b2928f607..8320b9ee4e 100644
--- a/libs/gltfio/src/DependencyGraph.h
+++ b/libs/gltfio/src/DependencyGraph.h
@@ -118,8 +118,8 @@ private:
     TextureNode* getStatus(filament::Texture* texture);
 
     // The following maps contain the directed edges in the graph.
-    tsl::robin_map<Entity, EntityNode> mEntityToMaterial;
-    tsl::robin_map<Material*, tsl::robin_set<Entity>> mMaterialToEntity;
+    tsl::robin_map<Entity, EntityNode, Entity::Hasher> mEntityToMaterial;
+    tsl::robin_map<Material*, tsl::robin_set<Entity, Entity::Hasher>> mMaterialToEntity;
     tsl::robin_map<Material*, MaterialNode> mMaterialToTexture;
     tsl::robin_map<filament::Texture*, tsl::robin_set<Material*>> mTextureToMaterial;
 
diff --git a/libs/gltfio/src/FFilamentInstance.h b/libs/gltfio/src/FFilamentInstance.h
index 52cfdd77fa..8423147e1c 100644
--- a/libs/gltfio/src/FFilamentInstance.h
+++ b/libs/gltfio/src/FFilamentInstance.h
@@ -55,7 +55,7 @@ struct Skin {
 
     // The set of all nodes that are influenced by this skin.
     // This is initially gleaned from the glTF file using the "skin" attribute of each node.
-    tsl::robin_set<utils::Entity> targets;
+    tsl::robin_set<utils::Entity, utils::Entity::Hasher> targets;
 };
 
 struct VariantMapping {
diff --git a/libs/image/src/ImageSampler.cpp b/libs/image/src/ImageSampler.cpp
index 98073c4894..d922e505bc 100644
--- a/libs/image/src/ImageSampler.cpp
+++ b/libs/image/src/ImageSampler.cpp
@@ -364,7 +364,7 @@ uint32_t getMipmapCount(const LinearImage& source) {
 Filter filterFromString(const char* rawname) {
     using namespace utils;
     using std::unordered_map;
-    static const unordered_map<StaticString, Filter> map = {
+    static const unordered_map<StaticString, Filter, StaticString::Hasher> map = {
         { "BOX", Filter::BOX},
         { "NEAREST", Filter::NEAREST},
         { "HERMITE", Filter::HERMITE},
diff --git a/libs/utils/benchmark/benchmark_binary_search.cpp b/libs/utils/benchmark/benchmark_binary_search.cpp
index 110a9c4088..376d59ed1d 100644
--- a/libs/utils/benchmark/benchmark_binary_search.cpp
+++ b/libs/utils/benchmark/benchmark_binary_search.cpp
@@ -16,14 +16,12 @@
 
 #include "PerformanceCounters.h"
 
-#include <utils/algorithm.h>
 #include <utils/compiler.h>
 
 #include <benchmark/benchmark.h>
 
 #include <random>
 #include <vector>
-#include <iostream>
 
 using namespace utils;
 
@@ -95,70 +93,5 @@ BENCHMARK_DEFINE_F(BinarySearch, stdLowerBound)(benchmark::State& state) {
     }
 }
 
-BENCHMARK_DEFINE_F(BinarySearch, utilsLowerBound)(benchmark::State& state) {
-    auto first = data.begin();
-    auto last = data.begin() + state.range(0);
-    std::vector<value_type> indices = prepareItems(state.range(0));
-    value_type const* ip = indices.data();
-    size_t i = 0;
-
-    {
-        PerformanceCounters pc(state);
-        for (auto _ : state) {
-            auto item = ip[i++ % state.range(0)];
-            auto const& pos = utils::lower_bound(first, last, item);
-            benchmark::DoNotOptimize(pos);
-        }
-    }
-}
-
-BENCHMARK_DEFINE_F(BinarySearch, utilsLowerBoundPOT)(benchmark::State& state) {
-    auto first = data.begin();
-    auto last = data.begin() + state.range(0);
-    std::vector<value_type> indices = prepareItems(state.range(0));
-    value_type const* ip = indices.data();
-    size_t i = 0;
-
-    {
-        PerformanceCounters pc(state);
-        for (auto _ : state) {
-            auto item = ip[i++ % state.range(0)];
-            auto const& pos = utils::lower_bound(first, last, item, {}, true);
-            benchmark::DoNotOptimize(pos);
-        }
-    }
-}
-
-BENCHMARK_DEFINE_F(BinarySearch, utilsLowerBound4096)(benchmark::State& state) {
-    auto first = data.begin();
-    auto last = data.begin() + 4096;
-    std::vector<value_type> indices = prepareItems(4096);
-    value_type const* ip = indices.data();
-    size_t i = 0;
-
-    {
-        PerformanceCounters pc(state);
-        for (auto _ : state) {
-            auto item = ip[i++ % 4096];
-            auto const& pos = utils::lower_bound(first, last, item, {}, true);
-            benchmark::DoNotOptimize(pos);
-        }
-    }
-}
-
 BENCHMARK_REGISTER_F(BinarySearch, linearSearch)->Range(2, 1<<20);
 BENCHMARK_REGISTER_F(BinarySearch, stdLowerBound)->Range(2, 1<<20);
-BENCHMARK_REGISTER_F(BinarySearch, utilsLowerBound)->Range(2, 1<<20);
-BENCHMARK_REGISTER_F(BinarySearch, utilsLowerBoundPOT)
-        ->Arg(2)
-        ->Arg(4)
-        ->Arg(16)
-        ->Arg(32)
-        ->Arg(64)
-        ->Arg(256)
-        ->Arg(4096)
-        ->Arg(32768)
-        ->Arg(262144)
-        ->Arg(1048576);
-
-BENCHMARK_REGISTER_F(BinarySearch, utilsLowerBound4096);
diff --git a/libs/utils/include/utils/CString.h b/libs/utils/include/utils/CString.h
index da809d11cf..09f3d2ca6a 100644
--- a/libs/utils/include/utils/CString.h
+++ b/libs/utils/include/utils/CString.h
@@ -79,7 +79,7 @@ public:
     using const_pointer   = const value_type*;
     using const_iterator  = const value_type*;
 
-    constexpr StaticString() noexcept = default;
+    constexpr StaticString() noexcept {} // NOLINT(modernize-use-equals-default), Ubuntu compiler bug
 
     // initialization from a string literal
     template<size_t N>
@@ -149,6 +149,14 @@ public:
 
     size_type getHash() const noexcept { return mHash; }
 
+    struct Hasher {
+        typedef StaticString argument_type;
+        typedef size_t result_type;
+        result_type operator()(const argument_type& s) const noexcept {
+            return s.getHash();
+        }
+    };
+
 private:
     const_pointer mString = nullptr;
     size_type mLength = 0;
@@ -200,7 +208,7 @@ public:
     using iterator        = value_type*;
     using const_iterator  = const value_type*;
 
-    CString() noexcept = default;
+    CString() noexcept {} // NOLINT(modernize-use-equals-default), Ubuntu compiler bug
 
     // Allocates memory and appends a null. This constructor can be used to hold arbitrary data
     // inside the string (i.e. it can contain nulls or non-ASCII encodings).
@@ -220,7 +228,7 @@ public:
             : CString(other, N - 1) {
     }
 
-    CString(StaticString const& s) : CString(s.c_str(), s.size()) {}
+    CString(StaticString const& s) : CString(s.c_str(), s.size()) {} // NOLINT(google-explicit-constructor)
 
     CString(const CString& rhs);
 
@@ -309,11 +317,19 @@ public:
     }
 
     // placement new declared as "throw" to avoid the compiler's null-check
-    inline void* operator new(size_t size, void* ptr) {
+    inline void* operator new(size_t, void* ptr) {
         assert(ptr);
         return ptr;
     }
 
+    struct Hasher : private hashCStrings {
+        typedef CString argument_type;
+        typedef size_t result_type;
+        result_type operator()(const argument_type& s) const noexcept {
+            return hashCStrings::operator()(s.c_str());
+        }
+    };
+
 private:
     struct Data {
         size_type length;
@@ -365,34 +381,4 @@ CString to_string(T value) noexcept;
 
 } // namespace utils
 
-// FIXME: how could we not include this one?
-// needed for std::hash, since implementation is inline, this would not cause
-// binaries incompatibilities if another STL version was used.
-#include <functional>
-
-namespace std {
-
-//! \privatesection
-template<>
-struct hash<utils::CString> {
-    typedef utils::CString argument_type;
-    typedef size_t result_type;
-    utils::hashCStrings hasher;
-    size_t operator()(const utils::CString& s) const noexcept {
-        return hasher(s.c_str());
-    }
-};
-
-//! \privatesection
-template<>
-struct hash<utils::StaticString> {
-    typedef utils::StaticString argument_type;
-    typedef size_t result_type;
-    size_t operator()(const utils::StaticString& s) const noexcept {
-        return s.getHash();
-    }
-};
-
-} // namespace std
-
 #endif // TNT_UTILS_CSTRING_H
diff --git a/libs/utils/include/utils/Entity.h b/libs/utils/include/utils/Entity.h
index 74f417aaaa..58fdf606ae 100644
--- a/libs/utils/include/utils/Entity.h
+++ b/libs/utils/include/utils/Entity.h
@@ -19,9 +19,6 @@
 
 #include <utils/compiler.h>
 
-// FIXME: could we get rid of <functional>
-#include <functional>   // for std::hash
-
 #include <stdint.h>
 #include <stddef.h>
 
@@ -30,7 +27,7 @@ namespace utils {
 class UTILS_PUBLIC Entity {
 public:
     // this can be used to create an array of to-be-filled entities (see create())
-    Entity() noexcept = default;
+    Entity() noexcept { } // NOLINT(modernize-use-equals-default), Ubuntu compiler bug
 
     // Entities can be copied
     Entity(const Entity& e) noexcept = default;
@@ -68,10 +65,17 @@ public:
         return Entity{ Type(identity) };
     }
 
+    struct Hasher {
+        typedef Entity argument_type;
+        typedef size_t result_type;
+        result_type operator()(argument_type const& e) const {
+            return e.getId();
+        }
+    };
+
 private:
     friend class EntityManager;
     friend class EntityManagerImpl;
-    friend struct std::hash<Entity>;
     using Type = uint32_t;
 
     explicit Entity(Type identity) noexcept : mIdentity(identity) { }
@@ -81,18 +85,4 @@ private:
 
 } // namespace utils
 
-
-namespace std {
-
-template<>
-struct hash<utils::Entity> {
-    typedef utils::Entity argument_type;
-    typedef size_t result_type;
-    result_type operator()(argument_type const& e) const {
-        return e.getId();
-    }
-};
-
-} // namespace std
-
 #endif // TNT_UTILS_ENTITY_H
diff --git a/libs/utils/include/utils/Hash.h b/libs/utils/include/utils/Hash.h
index 8d0bd9ff16..f17dfc8655 100644
--- a/libs/utils/include/utils/Hash.h
+++ b/libs/utils/include/utils/Hash.h
@@ -22,8 +22,7 @@
 #include <stdint.h>
 #include <stddef.h>
 
-namespace utils {
-namespace hash {
+namespace utils::hash {
 
 // Hash function that takes an arbitrary swath of word-aligned data.
 inline uint32_t murmur3(const uint32_t* key, size_t wordCount, uint32_t seed) noexcept {
@@ -99,7 +98,6 @@ inline void combine_fast(size_t& seed, const T& v) noexcept {
     seed ^= hasher(v) << 1u;
 }
 
-} // namespace hash
-} // namespace utils
+} // namespace utils::hash
 
 #endif // TNT_UTILS_HASH_H
diff --git a/libs/utils/include/utils/NameComponentManager.h b/libs/utils/include/utils/NameComponentManager.h
index 62201d113a..9e31e4618d 100644
--- a/libs/utils/include/utils/NameComponentManager.h
+++ b/libs/utils/include/utils/NameComponentManager.h
@@ -17,40 +17,19 @@
 #ifndef TNT_UTILS_NAMECOMPONENTMANAGER_H
 #define TNT_UTILS_NAMECOMPONENTMANAGER_H
 
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
 #include <utils/compiler.h>
+#include <utils/CString.h>
 #include <utils/Entity.h>
 #include <utils/EntityInstance.h>
 #include <utils/SingleInstanceComponentManager.h>
 
-#include <functional>
+#include <stddef.h>
+#include <stdint.h>
 
 namespace utils {
 
 class EntityManager;
 
-namespace details {
-class SafeString {
-public:
-    SafeString() noexcept = default;
-    explicit SafeString(const char* str) noexcept : mCStr(strdup(str)) { }
-    SafeString(SafeString&& rhs) noexcept : mCStr(rhs.mCStr) { rhs.mCStr = nullptr; }
-    SafeString& operator=(SafeString&& rhs) noexcept {
-        std::swap(mCStr, rhs.mCStr);
-        return *this;
-    }
-    ~SafeString() { free((void*)mCStr); }
-    const char* c_str() const noexcept { return mCStr; }
-
-private:
-    char const* mCStr = nullptr;
-};
-} // namespace details
-
-
 /**
  * \class NameComponentManager NameComponentManager.h utils/NameComponentManager.h
  * \brief Allows clients to associate string labels with entities.
@@ -69,7 +48,7 @@ private:
  * printf("%s\n", names->getName(names->getInstance(myEntity));
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
-class UTILS_PUBLIC NameComponentManager : public SingleInstanceComponentManager<details::SafeString> {
+class UTILS_PUBLIC NameComponentManager : public SingleInstanceComponentManager<utils::CString> {
 public:
     using Instance = EntityInstance<NameComponentManager>;
 
@@ -93,7 +72,7 @@ public:
      * @return Non-zero handle if the entity has a name component, 0 otherwise.
      */
     Instance getInstance(Entity e) const noexcept {
-        return Instance(SingleInstanceComponentManager::getInstance(e));
+        return { SingleInstanceComponentManager::getInstance(e) };
     }
 
     /*! \cond PRIVATE */
diff --git a/libs/utils/include/utils/SingleInstanceComponentManager.h b/libs/utils/include/utils/SingleInstanceComponentManager.h
index 574d14a745..e728d6ee90 100644
--- a/libs/utils/include/utils/SingleInstanceComponentManager.h
+++ b/libs/utils/include/utils/SingleInstanceComponentManager.h
@@ -256,7 +256,7 @@ protected:
 
 private:
     // maps an entity to an instance index
-    tsl::robin_map<Entity, Instance> mInstanceMap;
+    tsl::robin_map<Entity, Instance, Entity::Hasher> mInstanceMap;
     default_random_engine mRng;
 };
 
diff --git a/libs/utils/include/utils/StructureOfArrays.h b/libs/utils/include/utils/StructureOfArrays.h
index dd879a6fa3..41cd8b890c 100644
--- a/libs/utils/include/utils/StructureOfArrays.h
+++ b/libs/utils/include/utils/StructureOfArrays.h
@@ -19,7 +19,6 @@
 
 #include <array>        // note: this is safe, see how std::array is used below (inline / private)
 #include <cstddef>
-#include <functional>
 #include <utility>
 
 #include <stddef.h>
diff --git a/libs/utils/include/utils/algorithm.h b/libs/utils/include/utils/algorithm.h
index 72240c2730..6d12ffc63a 100644
--- a/libs/utils/include/utils/algorithm.h
+++ b/libs/utils/include/utils/algorithm.h
@@ -19,7 +19,6 @@
 
 #include <utils/compiler.h>
 
-#include <functional>       // for std::less
 #include <type_traits>      // for std::enable_if
 
 #include <limits.h>
@@ -168,74 +167,6 @@ T log2i(T x) noexcept {
     return (sizeof(x) * 8 - 1u) - clz(x);
 }
 
-/*
- * branch-less version of std::lower_bound and std::upper_bound.
- * These versions are intended to be fully inlined, which only happens when the size
- * of the array is known at compile time. This code also performs better if the
- * array is a power-of-two in size.
- *
- * These code works even if the conditions above are not met, and becomes a less-branches
- * algorithm instead of a branch-less one!
- */
-
-template<typename RandomAccessIterator, typename T, typename COMPARE = typename std::less<T>>
-inline UTILS_PUBLIC
-RandomAccessIterator lower_bound(
-        RandomAccessIterator first, RandomAccessIterator last, const T& value,
-        COMPARE comp = std::less<T>(),
-        bool assume_power_of_two = false) {
-    size_t len = last - first;
-
-    if (!assume_power_of_two) {
-        // handle non power-of-two sized arrays. If it's POT, the next line is a no-op
-        // and gets optimized out if the size is known at compile time.
-        len = 1u << (31 - clz(uint32_t(len)));     // next power of two length / 2
-        size_t difference = (last - first) - len;
-        // If len was already a POT, then difference will be 0.
-        // We need to explicitly check this case to avoid dereferencing past the end of the array
-        first += !difference || comp(first[len], value) ? difference : 0;
-    }
-
-    while (len) {
-        // The number of repetitions here doesn't affect the result. We manually unroll the loop
-        // twice, to guarantee we have at least two iterations without branches (for the case
-        // where the size is not known at compile time
-        first += comp(first[len >>= 1u], value) ? len : 0;
-        first += comp(first[len >>= 1u], value) ? len : 0;
-    }
-    first += comp(*first, value);
-    return first;
-}
-
-template<typename RandomAccessIterator, typename T, typename COMPARE = typename std::less<T>>
-inline UTILS_PUBLIC
-RandomAccessIterator upper_bound(
-        RandomAccessIterator first, RandomAccessIterator last,
-        const T& value, COMPARE comp = std::less<T>(),
-        bool assume_power_of_two = false) {
-    size_t len = last - first;
-
-    if (!assume_power_of_two) {
-        // handle non power-of-two sized arrays. If it's POT, the next line is a no-op
-        // and gets optimized out if the size is known at compile time.
-        len = 1u << (31 - clz(uint32_t(len)));     // next power of two length / 2
-        size_t difference = (last - first) - len;
-        // If len was already a POT, then difference will be 0.
-        // We need to explicitly check this case to avoid dereferencing past the end of the array
-        first += !difference || comp(value, first[len]) ? 0 : difference;
-    }
-
-    while (len) {
-        // The number of repetitions here doesn't affect the result. We manually unroll the loop
-        // twice, to guarantee we have at least two iterations without branches (for the case
-        // where the size is not known at compile time
-        first += !comp(value, first[len >>= 1u]) ? len : 0;
-        first += !comp(value, first[len >>= 1u]) ? len : 0;
-    }
-    first += !comp(value, *first);
-    return first;
-}
-
 template<typename RandomAccessIterator, typename COMPARE>
 inline UTILS_PUBLIC
 RandomAccessIterator partition_point(
diff --git a/libs/utils/src/EntityManagerImpl.h b/libs/utils/src/EntityManagerImpl.h
index f8ea374b50..e9c7ef1699 100644
--- a/libs/utils/src/EntityManagerImpl.h
+++ b/libs/utils/src/EntityManagerImpl.h
@@ -178,7 +178,7 @@ private:
     tsl::robin_set<Listener*> mListeners;
 
 #if FILAMENT_UTILS_TRACK_ENTITIES
-    tsl::robin_map<Entity, CallStack> mDebugActiveEntities;
+    tsl::robin_map<Entity, CallStack, Entity::Hasher> mDebugActiveEntities;
 #endif
 };
 
diff --git a/libs/utils/src/NameComponentManager.cpp b/libs/utils/src/NameComponentManager.cpp
index b3fd2daedc..98bb3839a3 100644
--- a/libs/utils/src/NameComponentManager.cpp
+++ b/libs/utils/src/NameComponentManager.cpp
@@ -28,7 +28,7 @@ NameComponentManager::~NameComponentManager() = default;
 
 void NameComponentManager::setName(Instance instance, const char* name) noexcept {
     if (instance) {
-        elementAt<NAME>(instance) = details::SafeString{ name };
+        elementAt<NAME>(instance) = CString{ name };
     }
 }
 
diff --git a/libs/utils/test/test_CString.cpp b/libs/utils/test/test_CString.cpp
index 7333e69e1c..16ef2c2baa 100644
--- a/libs/utils/test/test_CString.cpp
+++ b/libs/utils/test/test_CString.cpp
@@ -36,7 +36,7 @@ TEST(StaticString, hash) {
     EXPECT_NE(a.getHash(), c.getHash());
     EXPECT_NE(b.getHash(), c.getHash());
 
-    std::hash<StaticString> ha;
+    StaticString::Hasher ha;
     EXPECT_EQ(ha(a), a.getHash());
 }
 
diff --git a/libs/utils/test/test_algorithm.cpp b/libs/utils/test/test_algorithm.cpp
index 97f4401ad8..fa36aff0dc 100644
--- a/libs/utils/test/test_algorithm.cpp
+++ b/libs/utils/test/test_algorithm.cpp
@@ -138,91 +138,6 @@ TEST(AlgorithmTest, popcount) {
     }
 }
 
-TEST(AlgorithmTest, UpperBounds) {
-    int* r;
-    int array[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };
-
-    for (int i = 0; i < 8; i++) {
-        r = utils::upper_bound(std::begin(array), std::end(array), array[i]);
-        EXPECT_EQ(i + 1, r - std::begin(array));
-    }
-
-    r = utils::upper_bound(std::begin(array), std::end(array), 100);
-    EXPECT_EQ(std::end(array), r);
-
-    r = utils::upper_bound(std::begin(array), std::end(array), -1);
-    EXPECT_EQ(std::begin(array), r);
-
-
-    int array2[8] = { 0, 0, 0, 1, 1, 1, 2, 2 };
-    r = utils::upper_bound(std::begin(array2), std::end(array2), 0);
-    EXPECT_EQ(std::begin(array2) + 3, r);
-
-    r = utils::upper_bound(std::begin(array2), std::end(array2), 1);
-    EXPECT_EQ(std::begin(array2) + 6, r);
-
-    r = utils::upper_bound(std::begin(array2), std::end(array2), 2);
-    EXPECT_EQ(std::end(array2), r);
-
-
-    int arrayNPotEven[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
-    for (int i = 0; i < 10; i++) {
-        r = utils::upper_bound(std::begin(arrayNPotEven), std::end(arrayNPotEven), arrayNPotEven[i]);
-        EXPECT_EQ(i + 1, r - std::begin(arrayNPotEven));
-    }
-
-    int arrayNPotOdd[15] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 };
-    for (int i = 0; i < 15; i++) {
-        r = utils::upper_bound(std::begin(arrayNPotOdd), std::end(arrayNPotOdd), arrayNPotOdd[i]);
-        EXPECT_EQ(i + 1, r - std::begin(arrayNPotOdd));
-    }
-
-    std::array<int, 4> arr = {{1, 10, 15, 50}};
-    EXPECT_EQ(50, *utils::upper_bound(arr.begin(), arr.end(), 15));
-}
-
-TEST(AlgorithmTest, LowerBounds) {
-    int* r;
-    int array[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };
-
-    for (int i = 0; i < 8; i++) {
-        r = utils::lower_bound(std::begin(array), std::end(array), array[i]);
-        EXPECT_EQ(i, r - std::begin(array));
-    }
-
-    r = utils::lower_bound(std::begin(array), std::end(array), 100);
-    EXPECT_EQ(std::end(array), r);
-
-    r = utils::lower_bound(std::begin(array), std::end(array), -1);
-    EXPECT_EQ(std::begin(array), r);
-
-
-    int array2[8] = { 0, 0, 0, 1, 1, 1, 2, 2 };
-    r = utils::lower_bound(std::begin(array2), std::end(array2), 0);
-    EXPECT_EQ(std::begin(array2), r);
-
-    r = utils::lower_bound(std::begin(array2), std::end(array2), 1);
-    EXPECT_EQ(std::begin(array2) + 3, r);
-
-    r = utils::lower_bound(std::begin(array2), std::end(array2), 2);
-    EXPECT_EQ(std::begin(array2) + 6, r);
-
-    int arrayNPotEven[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
-    for (int i = 0; i < 10; i++) {
-        r = utils::lower_bound(std::begin(arrayNPotEven), std::end(arrayNPotEven), arrayNPotEven[i]);
-        EXPECT_EQ(i, r - std::begin(arrayNPotEven));
-    }
-
-    int arrayNPotOdd[15] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 };
-    for (int i = 0; i < 15; i++) {
-        r = utils::lower_bound(std::begin(arrayNPotOdd), std::end(arrayNPotOdd), arrayNPotOdd[i]);
-        EXPECT_EQ(i, r - std::begin(arrayNPotOdd));
-    }
-
-    std::array<int, 4> arr = {{1, 10, 15, 50}};
-    EXPECT_EQ(15, *utils::lower_bound(arr.begin(), arr.end(), 15));
-}
-
 TEST(AlgorithmTest, Partition) {
     int* r;
     int array[8] = { 2, 5, 4, 8, 9, 9, 9, 9 };
diff --git a/libs/viewer/include/viewer/ViewerGui.h b/libs/viewer/include/viewer/ViewerGui.h
index 348b0870ab..8192c32ee7 100644
--- a/libs/viewer/include/viewer/ViewerGui.h
+++ b/libs/viewer/include/viewer/ViewerGui.h
@@ -36,6 +36,7 @@
 #include <math/mat4.h>
 #include <math/vec3.h>
 
+#include <functional>
 #include <vector>
 
 namespace filagui {