Re: [Boost-users] [Q] using boost operators return types

Hi, please ignore this last question I figured out the problem I was using decPlus which adds 0 to the argument and I needed to use decAdd (which adds the two numbers) thank you again, Vlad On Mon, 23 Mar 2009 12:54 -0400, "V S P" wrote:

Thank you for the reply

I am still a bit lost

for example, the doc says

subtractable<T>

produces T operator-(const T&, const T&)

It requires: " T temp(t); temp -= t1. "

so does this mean T& operator -= (const T& ) ?

--- this is a separate question:

I have implemented the <addable> tempalte with += (as in the point example, but made it return a reference)

then I do cmoney_t a("300"); cmoney_t b("100");

a+=b;

and I see in the debugger that the *this in the operator += points to 100, not to 300

I am sure I am doing something wrong, but I thought in the += operator, *this would mean the value of "a" variable not "b".

Is at least my understanding correct, that *this should be pointing to 300, and not 100?

thank you again, Vlad

On Mon, 23 Mar 2009 10:41 -0500, "Alan M. Carroll" wrote:

...

At 09:55 AM 3/23/2009, V S P wrote:

...

I am using this example http://www.boost.org/doc/libs/1_38_0/libs/utility/operators.htm#example

but cannot understand why object is returned from those operators and not an object reference

That certainly is odd. It means that the following code will not work as expected:

point x(0,0), y(1,0), z(0,1); (x += y) += z; // x is (1,0), not (1,1).

...

second, I do not quite understand, what exactly is a set of 'automatically generated' operators and would I figure that out.

It is documented in the comments of the example you cite, and listed in the table[1] just below.

[1] http://www.boost.org/doc/libs/1_38_0/libs/utility/operators.htm#smpl_oprs

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users -- V S P toreason@fastmail.fm

-- http://www.fastmail.fm - I mean, what is it about a decent email service?

-- V S P toreason@fastmail.fm -- http://www.fastmail.fm - Or how I learned to stop worrying and love email again