[gcc4.9] Make constexpr usage compatible with GCC 4.9

11 files changed, 36 insertions, 25 deletions

diff --git a/include/mbgl/map/mode.hpp b/include/mbgl/map/mode.hpp
index afec5c0a08..05de2df22c 100644
--- a/include/mbgl/map/mode.hpp
+++ b/include/mbgl/map/mode.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/util/util.hpp>
 #include <mbgl/util/traits.hpp>
 
 #include <cstdint>
@@ -51,23 +52,23 @@ enum class MapDebugOptions : EnumType {
 #endif // MBGL_USE_GLES2
 };
 
-constexpr MapDebugOptions operator|(MapDebugOptions lhs, MapDebugOptions rhs) {
+MBGL_CONSTEXPR MapDebugOptions operator|(MapDebugOptions lhs, MapDebugOptions rhs) {
     return MapDebugOptions(mbgl::underlying_type(lhs) | mbgl::underlying_type(rhs));
 }
 
-constexpr MapDebugOptions& operator|=(MapDebugOptions& lhs, MapDebugOptions rhs) {
+MBGL_CONSTEXPR MapDebugOptions& operator|=(MapDebugOptions& lhs, MapDebugOptions rhs) {
     return (lhs = MapDebugOptions(mbgl::underlying_type(lhs) | mbgl::underlying_type(rhs)));
 }
 
-constexpr bool operator&(MapDebugOptions lhs, MapDebugOptions rhs) {
+MBGL_CONSTEXPR bool operator&(MapDebugOptions lhs, MapDebugOptions rhs) {
     return mbgl::underlying_type(lhs) & mbgl::underlying_type(rhs);
 }
 
-constexpr MapDebugOptions& operator&=(MapDebugOptions& lhs, MapDebugOptions rhs) {
+MBGL_CONSTEXPR MapDebugOptions& operator&=(MapDebugOptions& lhs, MapDebugOptions rhs) {
     return (lhs = MapDebugOptions(mbgl::underlying_type(lhs) & mbgl::underlying_type(rhs)));
 }
 
-constexpr MapDebugOptions operator~(MapDebugOptions value) {
+MBGL_CONSTEXPR MapDebugOptions operator~(MapDebugOptions value) {
     return MapDebugOptions(~mbgl::underlying_type(value));
 }
 
diff --git a/include/mbgl/util/color.hpp b/include/mbgl/util/color.hpp
index 300d7fae82..b595fdb1d7 100644
--- a/include/mbgl/util/color.hpp
+++ b/include/mbgl/util/color.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/util/optional.hpp>
+#include <mbgl/util/util.hpp>
 
 #include <cassert>
 #include <string>
diff --git a/include/mbgl/util/constants.hpp b/include/mbgl/util/constants.hpp
index 85e19c2ff0..a5a83287bc 100644
--- a/include/mbgl/util/constants.hpp
+++ b/include/mbgl/util/constants.hpp
@@ -2,6 +2,7 @@
 
 #include <mbgl/util/chrono.hpp>
 #include <mbgl/util/unitbezier.hpp>
+#include <mbgl/util/util.hpp>
 
 #include <cmath>
 #include <string>
@@ -43,7 +44,7 @@ constexpr uint64_t DEFAULT_MAX_CACHE_SIZE = 50 * 1024 * 1024;
 constexpr Duration DEFAULT_FADE_DURATION = Milliseconds(300);
 constexpr Seconds CLOCK_SKEW_RETRY_TIMEOUT { 30 };
 
-constexpr UnitBezier DEFAULT_TRANSITION_EASE = { 0, 0, 0.25, 1 };
+const UnitBezier DEFAULT_TRANSITION_EASE = { 0, 0, 0.25, 1 };
     
 constexpr int DEFAULT_RATE_LIMIT_TIMEOUT = 5;
 
diff --git a/include/mbgl/util/convert.hpp b/include/mbgl/util/convert.hpp
index c2b3d9950d..bedb1a4a08 100644
--- a/include/mbgl/util/convert.hpp
+++ b/include/mbgl/util/convert.hpp
@@ -1,3 +1,5 @@
+#include <mbgl/util/util.hpp>
+
 #include <array>
 #include <type_traits>
 #include <utility>
@@ -7,7 +9,7 @@ namespace util {
 
 template<typename To, typename From, std::size_t Size,
          typename = std::enable_if_t<std::is_convertible<From, To>::value>>
-constexpr std::array<To, Size> convert(const std::array<From, Size>&from) {
+MBGL_CONSTEXPR std::array<To, Size> convert(const std::array<From, Size>&from) {
     std::array<To, Size> to {};
     std::copy(std::begin(from), std::end(from), std::begin(to));
     return to;
diff --git a/include/mbgl/util/unitbezier.hpp b/include/mbgl/util/unitbezier.hpp
index 3a4994917b..16e356ac6e 100644
--- a/include/mbgl/util/unitbezier.hpp
+++ b/include/mbgl/util/unitbezier.hpp
@@ -25,6 +25,8 @@
 
 #pragma once
 
+#include <mbgl/util/util.hpp>
+
 #include <cmath>
 
 namespace mbgl {
@@ -32,7 +34,7 @@ namespace util {
 
 struct UnitBezier {
     // Calculate the polynomial coefficients, implicit first and last control points are (0,0) and (1,1).
-    constexpr UnitBezier(double p1x, double p1y, double p2x, double p2y)
+    MBGL_CONSTEXPR UnitBezier(double p1x, double p1y, double p2x, double p2y)
         : cx(3.0 * p1x)
         , bx(3.0 * (p2x - p1x) - cx)
         , ax(1.0 - cx - bx)
diff --git a/include/mbgl/util/util.hpp b/include/mbgl/util/util.hpp
index c5a7cb3780..7960b40299 100644
--- a/include/mbgl/util/util.hpp
+++ b/include/mbgl/util/util.hpp
@@ -12,3 +12,10 @@
 #define MBGL_VERIFY_THREAD(tid)
 
 #endif
+
+// GCC 4.9 compatibility
+#if !defined(__GNUC__) || __GNUC__ >= 5
+#define MBGL_CONSTEXPR constexpr
+#else
+#define MBGL_CONSTEXPR inline
+#endif
diff --git a/src/mbgl/gl/attribute.hpp b/src/mbgl/gl/attribute.hpp
index e45014127b..95945bca64 100644
--- a/src/mbgl/gl/attribute.hpp
+++ b/src/mbgl/gl/attribute.hpp
@@ -148,11 +148,8 @@ public:
     using State = IndexedTuple<TypeList<As...>, TypeList<typename As::State...>>;
     using Vertex = detail::Vertex<As...>;
 
-    template <class A>
-    static constexpr std::size_t Index = TypeIndex<A, As...>::value;
-
     static State state(const ProgramID& id) {
-        return State { typename As::State(bindAttributeLocation(id, Index<As>, As::name))... };
+        return State { typename As::State(bindAttributeLocation(id, TypeIndex<As, As...>::value, As::name))... };
     }
 
     static std::function<void (std::size_t)> binder(const State& state) {
@@ -162,7 +159,7 @@ public:
                                           state.template get<As>().type,
                                           sizeof(Vertex),
                                           vertexOffset,
-                                          Vertex::attributeOffsets[Index<As>]), 0)... });
+                                          Vertex::attributeOffsets[TypeIndex<As, As...>::value]), 0)... });
         };
     }
 };
diff --git a/src/mbgl/gl/gl.cpp b/src/mbgl/gl/gl.cpp
index 8999468dbd..bd6d7b192d 100644
--- a/src/mbgl/gl/gl.cpp
+++ b/src/mbgl/gl/gl.cpp
@@ -1,12 +1,13 @@
 #include <mbgl/gl/gl.hpp>
 #include <mbgl/util/string.hpp>
+#include <mbgl/util/util.hpp>
 
 namespace mbgl {
 namespace gl {
 
 namespace {
 
-constexpr const char* stringFromError(GLenum err) {
+MBGL_CONSTEXPR const char* stringFromError(GLenum err) {
     switch (err) {
     case GL_INVALID_ENUM:
         return "GL_INVALID_ENUM";
diff --git a/src/mbgl/map/update.hpp b/src/mbgl/map/update.hpp
index 74ab22dd8a..6f7c103cb8 100644
--- a/src/mbgl/map/update.hpp
+++ b/src/mbgl/map/update.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/util/traits.hpp>
+#include <mbgl/util/util.hpp>
 
 namespace mbgl {
 
@@ -14,15 +15,15 @@ enum class Update {
     Layout                    = 1 << 8
 };
 
-constexpr Update operator|(Update lhs, Update rhs) {
+MBGL_CONSTEXPR Update operator|(Update lhs, Update rhs) {
     return Update(mbgl::underlying_type(lhs) | mbgl::underlying_type(rhs));
 }
 
-constexpr Update& operator|=(Update& lhs, const Update& rhs) {
+MBGL_CONSTEXPR Update& operator|=(Update& lhs, const Update& rhs) {
     return (lhs = lhs | rhs);
 }
 
-constexpr bool operator& (Update lhs, Update rhs) {
+MBGL_CONSTEXPR bool operator& (Update lhs, Update rhs) {
     return mbgl::underlying_type(lhs) & mbgl::underlying_type(rhs);
 }
 
diff --git a/src/mbgl/renderer/render_pass.hpp b/src/mbgl/renderer/render_pass.hpp
index d273e34ff7..ae2b923ba1 100644
--- a/src/mbgl/renderer/render_pass.hpp
+++ b/src/mbgl/renderer/render_pass.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/util/traits.hpp>
+#include <mbgl/util/util.hpp>
 
 #include <cstdint>
 
@@ -12,15 +13,15 @@ enum class RenderPass : uint8_t {
     Translucent = 1 << 1,
 };
 
-constexpr RenderPass operator|(RenderPass a, RenderPass b) {
+MBGL_CONSTEXPR RenderPass operator|(RenderPass a, RenderPass b) {
     return RenderPass(mbgl::underlying_type(a) | mbgl::underlying_type(b));
 }
 
-constexpr RenderPass& operator|=(RenderPass& a, RenderPass b) {
+MBGL_CONSTEXPR RenderPass& operator|=(RenderPass& a, RenderPass b) {
     return (a = a | b);
 }
 
-constexpr RenderPass operator&(RenderPass a, RenderPass b) {
+MBGL_CONSTEXPR RenderPass operator&(RenderPass a, RenderPass b) {
     return RenderPass(mbgl::underlying_type(a) & mbgl::underlying_type(b));
 }
 
diff --git a/src/mbgl/util/indexed_tuple.hpp b/src/mbgl/util/indexed_tuple.hpp
index 110e7dce12..c46f63f275 100644
--- a/src/mbgl/util/indexed_tuple.hpp
+++ b/src/mbgl/util/indexed_tuple.hpp
@@ -31,16 +31,13 @@ public:
     using std::tuple<Ts...>::tuple;
 
     template <class I>
-    static constexpr std::size_t Index = TypeIndex<I, Is...>::value;
-
-    template <class I>
     auto& get() {
-        return std::get<Index<I>>(*this);
+        return std::get<TypeIndex<I, Is...>::value>(*this);
     }
 
     template <class I>
     const auto& get() const {
-        return std::get<Index<I>>(*this);
+        return std::get<TypeIndex<I, Is...>::value>(*this);
     }
 };