color: Make trivial helpers constexpr

src/common/color.h

@@ -11,42 +11,42 @@
 namespace Color {
 
 /// Convert a 1-bit color component to 8 bit
-inline u8 Convert1To8(u8 value) {
+constexpr u8 Convert1To8(u8 value) {
     return value * 255;
 }
 
 /// Convert a 4-bit color component to 8 bit
-inline u8 Convert4To8(u8 value) {
+constexpr u8 Convert4To8(u8 value) {
     return (value << 4) | value;
 }
 
 /// Convert a 5-bit color component to 8 bit
-inline u8 Convert5To8(u8 value) {
+constexpr u8 Convert5To8(u8 value) {
     return (value << 3) | (value >> 2);
 }
 
 /// Convert a 6-bit color component to 8 bit
-inline u8 Convert6To8(u8 value) {
+constexpr u8 Convert6To8(u8 value) {
     return (value << 2) | (value >> 4);
 }
 
 /// Convert a 8-bit color component to 1 bit
-inline u8 Convert8To1(u8 value) {
+constexpr u8 Convert8To1(u8 value) {
     return value >> 7;
 }
 
 /// Convert a 8-bit color component to 4 bit
-inline u8 Convert8To4(u8 value) {
+constexpr u8 Convert8To4(u8 value) {
     return value >> 4;
 }
 
 /// Convert a 8-bit color component to 5 bit
-inline u8 Convert8To5(u8 value) {
+constexpr u8 Convert8To5(u8 value) {
     return value >> 3;
 }
 
 /// Convert a 8-bit color component to 6 bit
-inline u8 Convert8To6(u8 value) {
+constexpr u8 Convert8To6(u8 value) {
     return value >> 2;
 }