diff --git a/filament/src/Material.cpp b/filament/src/Material.cpp
index f07ce243dc..ad93ee2d99 100644
--- a/filament/src/Material.cpp
+++ b/filament/src/Material.cpp
@@ -302,8 +302,8 @@ Handle<HwProgram> FMaterial::getProgramSlow(uint8_t variantKey) const noexcept {
 
     Program pb;
     pb      .diagnostics(mName, variantKey)
-            .withVertexShader(vs)
-            .withFragmentShader(fs)
+            .withVertexShader(std::move(vs))
+            .withFragmentShader(std::move(fs))
             .withSamplerBindings(&mSamplerBindings)
             .addUniformBlock(BindingPoints::PER_VIEW, &UibGenerator::getPerViewUib())
             .addUniformBlock(BindingPoints::LIGHTS, &UibGenerator::getLightsUib())
diff --git a/filament/src/View.cpp b/filament/src/View.cpp
index 20b18b17cb..5a43ebd57f 100644
--- a/filament/src/View.cpp
+++ b/filament/src/View.cpp
@@ -39,6 +39,8 @@
 #include <math/scalar.h>
 #include <math/fast.h>
 
+#include <memory>
+
 using namespace math;
 using namespace utils;
 
diff --git a/filament/src/driver/Program.cpp b/filament/src/driver/Program.cpp
index 15b5c3ade6..d52fc9b81b 100644
--- a/filament/src/driver/Program.cpp
+++ b/filament/src/driver/Program.cpp
@@ -32,9 +32,14 @@ Program& Program::operator=(const Program& rhs) = default;
 Program& Program::operator=(Program&& rhs) noexcept = default;
 Program::~Program() noexcept = default;
 
-Program& Program::diagnostics(utils::CString name, uint8_t variant) {
-    using std::swap;
-    swap(mName, name);
+Program& Program::diagnostics(utils::CString const& name, uint8_t variant) {
+    mName = name;
+    mVariant = variant;
+    return *this;
+}
+
+Program& Program::diagnostics(utils::CString&& name, uint8_t variant) noexcept {
+    name.swap(mName);
     mVariant = variant;
     return *this;
 }
@@ -44,9 +49,13 @@ Program& Program::withSamplerBindings(const SamplerBindingMap* bindings) {
     return *this;
 }
 
-Program& Program::shader(Program::Shader shader, CString source) {
-    using std::swap;
-    swap(mShadersSource[size_t(shader)], source);
+Program& Program::shader(Program::Shader shader, CString const& source) {
+    mShadersSource[size_t(shader)] = source;
+    return *this;
+}
+
+Program& Program::shader(Program::Shader shader, CString&& source) noexcept {
+    source.swap(mShadersSource[size_t(shader)]);
     return *this;
 }
 
diff --git a/filament/src/driver/Program.h b/filament/src/driver/Program.h
index 15e344ec26..34abc1bb54 100644
--- a/filament/src/driver/Program.h
+++ b/filament/src/driver/Program.h
@@ -51,10 +51,12 @@ public:
     ~Program() noexcept;
 
     // sets the material name and variant for diagnostic purposes only
-    Program& diagnostics(utils::CString name, uint8_t variantKey = 0);
+    Program& diagnostics(utils::CString const& name, uint8_t variantKey = 0);
+    Program& diagnostics(utils::CString&& name, uint8_t variantKey = 0) noexcept;
 
     // sets one of the program's shader (e.g. vertex, fragment)
-    Program& shader(Shader shader, utils::CString source);
+    Program& shader(Shader shader, utils::CString const& source);
+    Program& shader(Shader shader, utils::CString&& source) noexcept;
 
     // sets a uniform interface block for this program
     Program& addUniformBlock(size_t index, const UniformInterfaceBlock* ib);
@@ -63,12 +65,12 @@ public:
     Program& addSamplerBlock(size_t index, const SamplerInterfaceBlock* ib);
 
     template <typename T>
-    Program& withVertexShader(T source) {
+    Program& withVertexShader(T&& source) {
         return shader(Shader::VERTEX, std::forward<T>(source));
     }
 
     template <typename T>
-    Program& withFragmentShader(T source) {
+    Program& withFragmentShader(T&& source) {
         return shader(Shader::FRAGMENT, std::forward<T>(source));
     }
 
diff --git a/libs/utils/include/utils/CString.h b/libs/utils/include/utils/CString.h
index 2838cf6ae0..a0507546cc 100644
--- a/libs/utils/include/utils/CString.h
+++ b/libs/utils/include/utils/CString.h
@@ -185,9 +185,7 @@ public:
     CString& operator=(const CString& rhs);
 
     CString& operator=(CString&& rhs) noexcept {
-        if (this != &rhs) {
-            this->swap(rhs);
-        }
+        this->swap(rhs);
         return *this;
     }
 
@@ -260,6 +258,12 @@ public:
         return begin()[size() - 1];
     }
 
+    // placement new declared as "throw" to avoid the compiler's null-check
+    inline void* operator new(size_t size, void* ptr) {
+        assert(ptr);
+        return ptr;
+    }
+
 private:
     struct Data {
         size_type length;
diff --git a/libs/utils/src/CString.cpp b/libs/utils/src/CString.cpp
index 459c2597cf..d39e6e86d1 100644
--- a/libs/utils/src/CString.cpp
+++ b/libs/utils/src/CString.cpp
@@ -18,6 +18,8 @@
 
 #include <utils/compiler.h>
 
+#include <memory>
+
 namespace utils {
 
 int StaticString::compare(const StaticString& rhs) const noexcept {
@@ -36,7 +38,8 @@ CString::CString(const char* cstr, size_type length) {
         Data* p = (Data*)malloc(sizeof(Data) + length + 1);
         p->length = length;
         mCStr = (value_type*)(p + 1);
-        memcpy(mCStr, cstr, length + 1);
+        // we don't use memcpy here to avoid a call to libc, the generated code is pretty good.
+        std::uninitialized_copy_n(cstr, length + 1, mCStr);
     }
 }