Re: Can you spot anything wrong with this class/structure?
"Victor Bazarov" <v.Abazarov@comAcast.net> wrote in message
news:EcydnclyxKrKR83anZ2dnUVZ_s2tnZ2d@comcast.com...
Jim Langston wrote:
I use a game engine using MSVC++ .net 2003 and have no problems.
Doesn't really sound like it, since you're posting this...
I have no problems with the code, but people who compile with DevC++ have
problems when the executable crashes.
Some users of DevC++ who use the same engine crash at times when a
copy of this structure is the return variable. I don't have access
to the code that is crashing, but the developer has been changing
functions that return the structure to return something else because
of this problem.
Personally, I don't see anything wrong with this structure and can't
imagine why it would be crashing in DevC++.
DevC++ is an IDE. How can a struct crash an IDE?
Anyway, without seeing the code that does crash, I can only make
a few suggestions, see below.
Aside from the all caps used outside of a macro which is frowned
upon, can you spot anything wrong with this strucutre? It looks
perfectly legitimite to me. ( I know the consructor should be using
an initializer list and I've suggested that ).
struct JVEC2
{
JVEC2(float x=0,float y=0){this->x=x;this->y=y;}
Ouch.
Yeah, I agree. Been trying to get him to change this.
// Supported operators
JVEC2 operator+(JVEC2 a) const {JVEC2 temp;temp.x = x + a.x;temp.y
= y + a.y;return temp;}
Ugh... Yechhh! Here is the pattern you need to follow:
JVEC2 operator+(JVEC2 const& a) const {
return JVEC2(x + a.x, y + a.y);
}
Hmm.. now that he has the constructor, yeah, he can do this. It woudl
simplify the code, but don't know if it could prevent a crash.
Rewrite all non-compound operators.
JVEC2 operator-(JVEC2 a) const {JVEC2 temp;temp.x = x - a.x;temp.y
= y - a.y;return temp;}
JVEC2 operator*(JVEC2 a) const {JVEC2 temp;temp.x = x * a.x;temp.y
= y * a.y;return temp;}
JVEC2 operator/(JVEC2 a) const {JVEC2 temp;temp.x = x / a.x;temp.y
= y / a.y;return temp;}
JVEC2 operator+(float a) const {JVEC2 temp;temp.x = x + a;temp.y =
y + a;return temp;}
JVEC2 operator-(float a) const {JVEC2 temp;temp.x = x - a;temp.y =
y - a;return temp;}
JVEC2 operator*(float a) const {JVEC2 temp;temp.x = x * a;temp.y =
y * a;return temp;}
JVEC2 operator/(float a) const {JVEC2 temp;temp.x = x / a;temp.y =
y / a;return temp;}
JVEC2 operator+=(JVEC2 a) {x += a.x;y += a.y;return *this;}
Ugh... Compound assignments should return a *reference*! And
they should take a ref to const!
What would they return a reference to though? If it's the temp, won't that
disappear? Which is correct:
JVEC2& operator-(const JVEC2 a) {x = x - a.x; y = y - a.y; return this;}
or
JVEC2& operator-(const JVEC2 a) const {JVEC2 temp;temp.x = x - a.x;temp.y
= y - a.y;return temp;}
JVEC2 operator*=(JVEC2 a) {x *= a.x;y *= a.y;return *this;}
JVEC2 operator-=(JVEC2 a) {x -= a.x;y -= a.y;return *this;}
JVEC2 operator/=(JVEC2 a) {x /= a.x;y /= a.y;return *this;}
JVEC2 operator+=(float a) {x += a;y += a;return *this;}
JVEC2 operator-=(float a) {x -= a;y -= a;return *this;}
JVEC2 operator*=(float a) {x *= a;y *= a;return *this;}
JVEC2 operator/=(float a) {x /= a;y /= a;return *this;}
bool operator == (JVEC2 a) const {if (x == a.x && y == a.y) return
true; else return false;}
bool operator != (JVEC2 a) const {if (x != a.x || y != a.y) return
true; else return false;}
JVEC2 operator + () const {JVEC2 t;t.x=+x;t.y=+y;return t;}
JVEC2 operator - () const {JVEC2 t;t.x=-x;t.y=-y;return t;}
Yikes! Same here
JVEC2 operator +() const { return *this; } // unary plus does
// nothing for floats
JVEC2 operator -() const { return JVEC2(-x, -y); }
// data
float x,y;
};
V