Specialize GLTypeToGLEnum in headers

src/libANGLE/queryconversions.cpp

@@ -86,17 +86,6 @@ QueryT CastStateValue(GLenum pname, NativeT value)
 
 }  // anonymous namespace
 
-template <>
-GLenum GLTypeToGLenum<GLint>::value = GL_INT;
-template <>
-GLenum GLTypeToGLenum<GLuint>::value = GL_UNSIGNED_INT;
-template <>
-GLenum GLTypeToGLenum<GLboolean>::value = GL_BOOL;
-template <>
-GLenum GLTypeToGLenum<GLint64>::value = GL_INT_64_ANGLEX;
-template <>
-GLenum GLTypeToGLenum<GLfloat>::value = GL_FLOAT;
-
 template <typename QueryT>
 void CastStateValues(Context *context, GLenum nativeType, GLenum pname,
                      unsigned int numParams, QueryT *outParams)

src/libANGLE/queryconversions.h

@@ -23,7 +23,33 @@ class Context;
 template <typename GLType>
 struct GLTypeToGLenum
 {
-    static GLenum value;
+    // static constexpr GLenum value;
+};
+
+template <>
+struct GLTypeToGLenum<GLint>
+{
+    static constexpr GLenum value = GL_INT;
+};
+template <>
+struct GLTypeToGLenum<GLuint>
+{
+    static constexpr GLenum value = GL_UNSIGNED_INT;
+};
+template <>
+struct GLTypeToGLenum<GLboolean>
+{
+    static constexpr GLenum value = GL_BOOL;
+};
+template <>
+struct GLTypeToGLenum<GLint64>
+{
+    static constexpr GLenum value = GL_INT_64_ANGLEX;
+};
+template <>
+struct GLTypeToGLenum<GLfloat>
+{
+    static constexpr GLenum value = GL_FLOAT;
 };
 
 // The GL state query API types are: bool, int, uint, float, int64