Mail Archives: djgpp/1997/06/28/17:32:06
"John M. Aldrich" <fighteer AT cs DOT com> writes:
> Gregary J Boyles wrote:
> What are they?
Pick an answer. Precompiled headers are...
* "precompiled" "headers".
* The main reason why people complain that gcc compares unfavorable in
compile-speed to commercial compilers. gcc doesn't have them.
* the result of compiling just headers, just *once*, dumping the
end-result to disk, and fetching it back for a body file that
includes that header.
* The main reason why ANSI C++/X3J16 says that #include <filename>,
unlike #include "filename", doesn't have to read a real file of that
* hard to implement because they have to be in sync between the
preprocessing stage and the symbol-lookup stage, have to react to
changes in the underlying "real" header, may be dependent on the
order in which files are included, and I strongly suspect that many
things you *wouldn't* do in a normal header, such as ending halfway
thru a declaration, you *couldn't* do in a precompiled one.
> And why would you want them?
Ask me that when I'm waiting for a long compile on a trivial change.
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