Casting this pointer to a number
Hello, I'd like to provide a function with an unique identifier: void f(size_t UniqueId); This function is going to be called from within class member functions like that: class a { a() { f((size_t)this); } }; Right now the old style cast works. The question is how do I make conversion using numeric_cast? If I use: f(boost::numeric_cast<size_t>(this)); I get a compilation error: error C2665: 'ceil' : none of the 3 overloads could convert all the argument types I guess another question is: should I bother replacing this old-style cast, maybe there is a better way to approach this situation in general? Thanks.
On Sun, Jan 13, 2008 at 08:40:51AM -0600, sj@sjcomp.com wrote:
I'd like to provide a function with an unique identifier:
Why? What is it going to do with the ID? Why not make the ID a void* pointer? And what semantics does this "unique identification" have? Once an object is deleted, another new'd object may get its address; I can hardly qualify that as "unique ID".
I guess another question is: should I bother replacing this old-style cast, maybe there is a better way to approach this situation in general?
reinterpret_cast. although, that's long and painful to type at every function invocation (so is the old-style cast), so I'd redefine f() as void f(void *pv) { size_t uid = reinterpret_cast<size_t>(pv); ... }
sj@sjcomp.com wrote:
Hello,
I'd like to provide a function with an unique identifier: void f(size_t UniqueId);
Why not generate a GUID as a unique identifier. I know there is functionality for that under Windows and I highly suspect there is functionality for generating a GUID under Linux and Mac.
Edward Diener wrote:
sj@sjcomp.com wrote:
Hello,
I'd like to provide a function with an unique identifier: void f(size_t UniqueId);
Why not generate a GUID as a unique identifier. I know there is functionality for that under Windows and I highly suspect there is functionality for generating a GUID under Linux and Mac.
Or boost.GUID -- provisionally accepted library. GUID v7 in the vault I believe is the latest version: http://www.boost-consulting.com/vault/ Jeff
participants (4)
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Edward Diener -
Jeff Garland -
sj＠sjcomp.com -
Zeljko Vrba