Previously the CHECK_HEADER_ADD_INCLUDE function defined the
`HAVE_<header>_H` preprocessor macros to value 0 or 1 whether the
`<header.h>` file was found. This syncs it with Autotools build system
where most of these macros are either undefined or defined to 1.
In possible edge cases where such macros might be intentionally used
like this without being aware that HAVE_HEADER_H can be 0 or 1 on
Windows:
| #ifdef HAVE_HEADER_H
| ...
| #endif
there is backwards incompatibility for PECL extensions in case the
header wouldn't exist on Windows such code wouldn't execute. However,
this is considered a bug if such case is present. From the Autotools
point of view, the check is correct though and should be used with
ifdef/defined() checks.
Help text is also synced to Autotools style:
`Define to 1 if you have the <header.h> header file.`
@cname currently refers to the constant name in C. However, it is not always a (constant) name, but sometimes a function invocation, so naming it as @cvalue would be more appropriate.
We add support for creating `VT_ERROR` variants via `__construct()`,
and allow casting to int via `variant_cast()` and `variant_set_type()`.
We do not, however, allow type conversion by other means, to avoid
otherwise easily introduced type confusion. VB(A) also only allows
explicit type conversion.
We also introduce `DISP_E_PARAMNOTFOUND` which might be the most
important `scode` for this purpose, since this allows to skip optional
parameters in method calls.
Closes GH-8886.
We substitute the construction magic with standard constructors, move
the ZPP checks to the beginning of the ctors, and also let the function
entries be generated from the stubs.
