Use inline constexpr for constants in header files

src/celengine/astro.h

@@ -223,21 +223,21 @@ namespace astro
     double meanEclipticObliquity(double jd);
 
     // epoch J2000: 12 UT on 1 Jan 2000
-    constexpr const double J2000            = 2451545.0;
-    constexpr const double speedOfLight     = 299792.458; // km/s
-    constexpr const double G                = 6.672e-11; // N m^2 / kg^2; gravitational constant
-    constexpr const double SolarMass        = 1.989e30;
-    constexpr const double EarthMass        = 5.972e24;
-    constexpr const double LunarMass        = 7.346e22;
-    constexpr const double JupiterMass      = 1.898e27;
+    constexpr inline double J2000            = 2451545.0;
+    constexpr inline double speedOfLight     = 299792.458; // km/s
+    constexpr inline double G                = 6.672e-11; // N m^2 / kg^2; gravitational constant
+    constexpr inline double SolarMass        = 1.989e30;
+    constexpr inline double EarthMass        = 5.972e24;
+    constexpr inline double LunarMass        = 7.346e22;
+    constexpr inline double JupiterMass      = 1.898e27;
 
     // Angle between J2000 mean equator and the ecliptic plane.
     // 23 deg 26' 21".448 (Seidelmann, _Explanatory Supplement to the
     // Astronomical Almanac_ (1992), eqn 3.222-1.
-    constexpr const double J2000Obliquity   = 23.4392911_deg;
+    constexpr inline double J2000Obliquity   = 23.4392911_deg;
 
-    constexpr const double SOLAR_IRRADIANCE = 1367.6; // Watts / m^2
-    constexpr const double SOLAR_POWER      = 3.8462e26;  // in Watts
+    constexpr inline double SOLAR_IRRADIANCE = 1367.6; // Watts / m^2
+    constexpr inline double SOLAR_POWER      = 3.8462e26;  // in Watts
 
 
     namespace literals

src/celengine/atmosphere.h

@@ -67,7 +67,7 @@ class Atmosphere
 // to render. The radius of the sphere is the height at which the
 // density of the atmosphere falls to the extinction threshold, i.e.
 // -H * ln(extinctionThreshold)
-constexpr const float AtmosphereExtinctionThreshold = 0.05f;
+constexpr inline float AtmosphereExtinctionThreshold = 0.05f;
 
 #endif // _CELENGINE_ATMOSPHERE_H_
 

src/celengine/deepskyobj.h

@@ -26,7 +26,7 @@ class Selection;
 class Renderer;
 struct Matrices;
 
-constexpr const float DSO_DEFAULT_ABS_MAGNITUDE = -1000.0f;
+constexpr inline float DSO_DEFAULT_ABS_MAGNITUDE = -1000.0f;
 
 class Nebula;
 class Galaxy;

src/celengine/dsodb.h

@@ -21,10 +21,10 @@
 #include <celengine/parser.h>
 
 
-constexpr const unsigned int MAX_DSO_NAMES = 10;
+constexpr inline unsigned int MAX_DSO_NAMES = 10;
 
 // 100 Gly - on the order of the current size of the universe
-constexpr const float DSO_OCTREE_ROOT_SIZE = 1.0e11f;
+constexpr inline float DSO_OCTREE_ROOT_SIZE = 1.0e11f;
 
 //NOTE: this one and starDatabase should be derived from a common base class since they share lots of code and functionality.
 class DSODatabase

src/celengine/pointstarrenderer.h

@@ -22,11 +22,11 @@ class StarDatabase;
 
 // TODO: move these variables to PointStarRenderer class
 // without adding a variable. Requires C++17
-constexpr const float StarDistanceLimit     = 1.0e6f;
+constexpr inline float StarDistanceLimit     = 1.0e6f;
 // Star disc size in pixels
-constexpr const float BaseStarDiscSize      = 5.0f;
-constexpr const float MaxScaledDiscStarSize = 8.0f;
-constexpr const float GlareOpacity          = 0.65f;
+constexpr inline float BaseStarDiscSize      = 5.0f;
+constexpr inline float MaxScaledDiscStarSize = 8.0f;
+constexpr inline float GlareOpacity          = 0.65f;
 
 class PointStarRenderer : public ObjectRenderer<Star, float>
 {

src/tools/cmod/cmodview/glsupport.h

@@ -13,7 +13,7 @@
 namespace celestia::gl
 {
 
-constexpr const int GL_2_1 = 21;
+constexpr inline int GL_2_1 = 21;
 
 extern bool ARB_shader_objects;
 extern bool ARB_shading_language_100;