message: Drop constexpr to work around gcc 5 compiler bug
diff: @@ -82,7 +82,7 @@ private:
  Matrix4f(const float *d) { memcpy(f, d, sizeof(Matrix4f)); }
  friend class Quatf;
  - constexpr inline size_t matIdx(const size_t x, const size_t y) const { return x + y * 4; }
  + inline size_t matIdx(const size_t x, const size_t y) const { return x + y * 4; }
  float f[16];
  };
  @@ -99,7 +99,7 @@ public:
  const float *Data() const { return &f[0]; }
  void SetFrom(float data[9]) { memcpy(f, data, sizeof(Matrix3f)); }
  private:
  - constexpr inline size_t matIdx(const size_t x, const size_t y) const { return x + y * 3; }
  + inline size_t matIdx(const size_t x, const size_t y) const { return x + y * 3; }
  float f[9];
  };
  @@ -123,6 +123,6 @@ public:
  const float *Data() const { return &f[0]; }
  void SetFrom(float data[4]) { memcpy(f, data, sizeof(Matrix2f)); }
  private:
  - constexpr inline size_t matIdx(const size_t x, const size_t y) const { return x + y * 2; }
  + inline size_t matIdx(const size_t x, const size_t y) const { return x + y * 2; }
  float f[4];
  };
  