David Abrahams wrote: > > Gabriel Dos Reis <[EMAIL PROTECTED]> writes: > > > David Abrahams <[EMAIL PROTECTED]> writes: > > > > | I disagree with your conclusion. As I've said elsewhere, &k can be a > > | compile-time constant in the same way that &X::k is a compile-time > > | constant. > > > > Certainly, you've said that. But that assertion by itself does not > > constitute a proof of the well-foundness of the attempted analogy or > > whether the analogy actually constitutes a proof. > > It's not intended to be proof in the mathematical sense; I doubt I > have the energy for that ;-), though I think MSVC probably constitutes > an existence proof.
Yeah. Indeed: <http://tinyurl.com/673e> http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore/html/_core_rules_and_limitations_for_tls.asp ".... The address of a thread local object is not considered constant, and any expression involving such an address is not considered a constant expression. In standard C, the effect of this is to forbid the use of the address of a thread local variable as an initializer for an object or pointer. For example, the following code will be flagged as an error by the C compiler: #define Thread __declspec( thread ) Thread int tls_i; int *p = &tls_i; //This will generate an error in C. This restriction does not apply in C++, however. Because C++ permits dynamic initialization of all objects, you can initialize an object with an expression that uses the address of a thread local variable. This is accomplished in the same way as the construction of thread local objects. For example, the code shown above will not generate an error when compiled as a C++ source file. Note that the address of a thread local variable is valid only as long as the thread in which the address was taken still exists. ...." regards, alexander. P.S. Kinda-funny stuff: "C++ does not allow such dynamic initialization of thread data because of possible future enhancements to the thread local storage facility." _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
