[core] use default instead of empty function body

include/mbgl/util/image.hpp

@@ -14,7 +14,7 @@ enum ImageAlphaMode {
 template <ImageAlphaMode Mode>
 class Image {
 public:
-    Image() {}
+    Image() = default;
 
     Image(size_t w, size_t h)
         : width(w),

include/mbgl/util/vec.hpp

@@ -16,7 +16,7 @@ struct vec2 {
 
     T x, y;
 
-    inline vec2() {}
+    inline vec2() = default;
 
     template<typename U = T, typename std::enable_if<std::numeric_limits<U>::has_quiet_NaN, int>::type = 0>
     inline vec2(null) : x(std::numeric_limits<T>::quiet_NaN()), y(std::numeric_limits<T>::quiet_NaN()) {}
@@ -24,7 +24,7 @@ struct vec2 {
     template<typename U = T, typename std::enable_if<!std::numeric_limits<U>::has_quiet_NaN, int>::type = 0>
     inline vec2(null) : x(std::numeric_limits<T>::min()), y(std::numeric_limits<T>::min()) {}
 
-    inline vec2(const vec2& o) : x(o.x), y(o.y) {}
+    inline vec2(const vec2& o) = default;
 
     template<typename U>
     inline vec2(const U& u) : x(u.x), y(u.y) {}
@@ -99,7 +99,7 @@ template <typename T = double>
 struct vec3 {
     T x, y, z;
 
-    inline vec3() {}
+    inline vec3() = default;
     inline vec3(const vec3& o) : x(o.x), y(o.y), z(o.z) {}
     inline vec3(T x_, T y_, T z_) : x(x_), y(y_), z(z_) {}
     inline bool operator==(const vec3& rhs) const {
@@ -111,7 +111,7 @@ template <typename T = double>
 struct vec4 {
     T x, y, z, w;
 
-    inline vec4() {}
+    inline vec4() = default;
     inline vec4(const vec4& o) : x(o.x), y(o.y), z(o.z), w(o.w) {}
     inline vec4(T x_, T y_, T z_, T w_) : x(x_), y(y_), z(z_), w(w_) {}
     inline bool operator==(const vec4& rhs) const {

platform/default/async_task.cpp

@@ -65,8 +65,7 @@ AsyncTask::AsyncTask(std::function<void()>&& fn)
     : impl(std::make_unique<Impl>(std::move(fn))) {
 }
 
-AsyncTask::~AsyncTask() {
-}
+AsyncTask::~AsyncTask() = default;
 
 void AsyncTask::send() {
     impl->maySend();

platform/default/timer.cpp

@@ -66,8 +66,7 @@ Timer::Timer()
     : impl(std::make_unique<Impl>()) {
 }
 
-Timer::~Timer() {
-}
+Timer::~Timer() = default;
 
 void Timer::start(Duration timeout, Duration repeat, std::function<void()>&& cb) {
     impl->start(std::chrono::duration_cast<std::chrono::milliseconds>(timeout).count(),

src/mbgl/renderer/bucket.hpp

@@ -30,7 +30,7 @@ public:
     // once or twice (for Opaque and Transparent render passes).
     virtual void render(Painter&, const StyleLayer&, const TileID&, const mat4&) = 0;
 
-    virtual ~Bucket() {}
+    virtual ~Bucket() = default;
 
     virtual bool hasData() const = 0;
 

src/mbgl/renderer/painter.cpp

@@ -48,8 +48,7 @@ Painter::Painter(MapData& data_, TransformState& state_)
     setup();
 }
 
-Painter::~Painter() {
-}
+Painter::~Painter() = default;
 
 bool Painter::needsAnimation() const {
     return frameHistory.needsAnimation(data.getDefaultFadeDuration());

src/mbgl/util/rect.hpp

@@ -5,7 +5,7 @@ namespace mbgl {
 
 template <typename T>
 struct Rect {
-    inline Rect() {}
+    inline Rect() = default;
     inline Rect(T x_, T y_, T w_, T h_) : x(x_), y(y_), w(w_), h(h_) {}
     T x = 0, y = 0;
     T w = 0, h = 0;

src/mbgl/util/transition.cpp

@@ -7,7 +7,7 @@ namespace mbgl { namespace util {
 
 UnitBezier ease(0, 0, 0.25, 1);
 
-transition::~transition() {}
+transition::~transition() = default;
 
 template <typename T>
 transition::state ease_transition<T>::update(const TimePoint& now) const {