[boost] Re: Math functions - requirements 'spec'

From: Thorsten Ottosen (nesotto_at_[hidden])
Date: 2004-11-04 12:47:17

"Paul A Bristow" <pbristow_at_[hidden]> wrote in message
news:E1CPhm8-0004eI-89_at_he203war.uk.vianw.net...
| Following the view of C and C++ Working groups at Redmond
| that a working implementation of my proposal for math functions
| was a necessary condition for consideration for a TR-2 standard,
|
| I have been skirmishing with the problems of converting
| Stephen Moshier's Cephes code into something that works for both C++ and C.
|
| Several issues have emerged, mainly revealing my ignorance with C
| - a state of bliss in which I would have preferred to remain ;-)
|
| 1  Should I no longer cater for non-compliant compilers (usually old-style
| function specifications?

yes.

| I only have MSVC 8.0 available.
|
| 2  How do I check that my code is Standard C compatible (as well as C++)?

compile with

/TC compile all files as .c
/TP compile all files as .cpp

| 3  How do I tell whether the compiler is a C compiler or a C++ compiler (for
| #if ing).
|   #if __cplusplus  #if _STDC__ ... ?

#if !defined(__cpluplus )
... we have C

| 5  Do I have to use exclusively C /* */ style comments :-((?  (Or can I
| assume that C compilers will understand // comments?)

why do you want to implement it for C also?

| I have also immediately come up against the problems of IEEE 754 compliance,
| argument checks, NaN, infs and exception throwing.
|
| 6  Should I assume IEEE 754 compliance and signal #error "Only works with
| IEEE compliant compilers"?

but this is not guaranteen by the standard, is it?

| 13  Do you also recommend making checking arguments optional (with #ifdefs)?
| So that those who want the ultimate in speed at any risk can switch checking
| off?

first make it work...

| Comments welcome.

good to see you working on this :-)

-Thorsten