Simplified and tested Texture move constructor/assignment.

Move constructor and move assignment is now noexcept and it just swaps
the data of the two instances instead of calling GL API, thus it can be
inline. Also removed unneded limitations in BufferTexture.

src/AbstractTexture.cpp

@@ -124,8 +124,12 @@ Int AbstractTexture::maxIntegerSamples() {
 }
 #endif
 
-void AbstractTexture::destroy() {
+AbstractTexture::AbstractTexture(GLenum target): _target(target) {
-    /* Moved out */
+    glGenTextures(1, &_id);
+}
+
+AbstractTexture::~AbstractTexture() {
+    /* Moved out, nothing to do */
     if(!_id) return;
 
     /* Remove all bindings */
@@ -135,30 +139,6 @@ void AbstractTexture::destroy() {
     glDeleteTextures(1, &_id);
 }
 
-void AbstractTexture::move() {
-    _id = 0;
-}
-
-AbstractTexture::AbstractTexture(GLenum target): _target(target) {
-    glGenTextures(1, &_id);
-}
-
-AbstractTexture::~AbstractTexture() { destroy(); }
-
-AbstractTexture::AbstractTexture(AbstractTexture&& other): _target(other._target), _id(other._id) {
-    other.move();
-}
-
-AbstractTexture& AbstractTexture::operator=(AbstractTexture&& other) {
-    destroy();
-
-    _target = other._target;
-    _id = other._id;
-
-    other.move();
-    return *this;
-}
-
 std::string AbstractTexture::label() const {
     return Context::current()->state().debug->getLabelImplementation(GL_TEXTURE, _id);
 }

src/AbstractTexture.h

@@ -158,13 +158,13 @@ class MAGNUM_EXPORT AbstractTexture: public AbstractObject {
         AbstractTexture(const AbstractTexture&) = delete;
 
         /** @brief Move constructor */
-        AbstractTexture(AbstractTexture&& other);
+        AbstractTexture(AbstractTexture&& other) noexcept;
 
         /** @brief Copying is not allowed */
         AbstractTexture& operator=(const AbstractTexture&) = delete;
 
         /** @brief Move assignment */
-        AbstractTexture& operator=(AbstractTexture&& other);
+        AbstractTexture& operator=(AbstractTexture&& other) noexcept;
 
         /**
          * @brief %Texture label
@@ -482,8 +482,6 @@ class MAGNUM_EXPORT AbstractTexture: public AbstractObject {
         #endif
         static InvalidateSubImageImplementation invalidateSubImageImplementation;
 
-        void MAGNUM_LOCAL destroy();
-        void MAGNUM_LOCAL move();
         ColorFormat MAGNUM_LOCAL imageFormatForInternalFormat(TextureFormat internalFormat);
         ColorType MAGNUM_LOCAL imageTypeForInternalFormat(TextureFormat internalFormat);
 
@@ -597,6 +595,16 @@ template<> struct MAGNUM_EXPORT AbstractTexture::DataHelper<3> {
 };
 #endif
 
+inline AbstractTexture::AbstractTexture(AbstractTexture&& other) noexcept: _target(other._target), _id(other._id) {
+    other._id = 0;
+}
+
+inline AbstractTexture& AbstractTexture::operator=(AbstractTexture&& other) noexcept {
+    std::swap(_target, other._target);
+    std::swap(_id, other._id);
+    return *this;
+}
+
 }
 
 #endif

src/BufferTexture.h

@@ -201,11 +201,6 @@ and respective function documentation for more information.
 class MAGNUM_EXPORT BufferTexture: private AbstractTexture {
     friend class Context;
 
-    BufferTexture(const BufferTexture&) = delete;
-    BufferTexture(BufferTexture&&) = delete;
-    BufferTexture& operator=(const BufferTexture&) = delete;
-    BufferTexture& operator=(BufferTexture&&) = delete;
-
     public:
         /** @copydoc AbstractTexture::maxLabelLength() */
         static Int maxLabelLength() { return AbstractTexture::maxLabelLength(); }

src/Test/AbstractTextureGLTest.cpp

@@ -33,11 +33,57 @@ class AbstractTextureGLTest: public AbstractOpenGLTester {
     public:
         explicit AbstractTextureGLTest();
 
+        void construct();
+        void constructCopy();
+        void constructMove();
+
         void label();
 };
 
 AbstractTextureGLTest::AbstractTextureGLTest() {
-    addTests({&AbstractTextureGLTest::label});
+    addTests({&AbstractTextureGLTest::construct,
+              &AbstractTextureGLTest::constructCopy,
+              &AbstractTextureGLTest::constructMove,
+
+              &AbstractTextureGLTest::label});
+}
+
+void AbstractTextureGLTest::construct() {
+    {
+        const Texture2D texture;
+
+        MAGNUM_VERIFY_NO_ERROR();
+        CORRADE_VERIFY(texture.id() > 0);
+    }
+
+    MAGNUM_VERIFY_NO_ERROR();
+}
+
+void AbstractTextureGLTest::constructCopy() {
+     CORRADE_VERIFY(!(std::is_constructible<Texture2D, const Texture2D&>{}));
+     CORRADE_VERIFY(!(std::is_assignable<Texture2D, const Texture2D&>{}));
+}
+
+void AbstractTextureGLTest::constructMove() {
+    Texture2D a;
+    const Int id = a.id();
+
+    MAGNUM_VERIFY_NO_ERROR();
+    CORRADE_VERIFY(id > 0);
+
+    Texture2D b(std::move(a));
+
+    CORRADE_COMPARE(a.id(), 0);
+    CORRADE_COMPARE(b.id(), id);
+
+    Texture2D c;
+    const Int cId = c.id();
+    c = std::move(b);
+
+    MAGNUM_VERIFY_NO_ERROR();
+    CORRADE_VERIFY(cId > 0);
+    CORRADE_COMPARE(b.id(), cId);
+    CORRADE_COMPARE(c.id(), id);
 }
 
 void AbstractTextureGLTest::label() {