July 2005 - Boost-users - lists.boost.org

Boost::regex assign/operator= 'problem'
by Stuart Dootson 01 Jul '05

01 Jul '05

Should an empty boost::regex raise a 'bad expression' exception when you assign it to another boost::regex object? It seems to me that an empty expression can't be bad - it hasn't had the chance to be good OR bad yet :-) The rationale for this is that I have an object that contains a boost::regex that is compiled on demand. The object is likely to be copied (into a std::vector), before the regex has been compiled (if it is ever compiled). I know I could use things like boost::optional<boost::regex>, or boost::scoped_ptr<boost::regex> (I am working round it currently), but this seems like an interesting corner case! Here's a minimal sample: #include <iostream> #include <boost/regex.hpp> int main(int, char**) { boost::regex re; try { re = boost::regex(); } catch (boost::bad_expression&) { std::cout << "It threw\n"; } return 0; } It'll output "It threw" on execution (environment = Windows 2000, VC7.1, Boost1.32.0). Stuart Dootson

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supressing "extra ;" warnings with GCC 3.4
by Dave Steffen 01 Jul '05

01 Jul '05

Hi folks, Tried to compile our code with GCC 3.4 last night; our default is to always keep the warning levels turned all the way up. I'm getting many errors of the "extra `;'" type, as the result of various preprocessor metaprogramming constructs. Specifically, if a macro expands to a function definition (silly example): #define FOO(T) \ inline T FOO(T i) { ... } FOO(int); FOO(double); The semicolons after the macro invocations give GCC 3.4 fits; but without the semicolons, it looks strange, editors can't indent, etc. Is anyone aware of a way to silence the "extra ;" errors? (I've looked through their docs, can't find anything; I suspect other Boost users have run across this.) Is there something I'm missing in the preprocessor library that handles this sort of thing? Any help appreciated! Thanks! ---------------------------------------------------------------------- Dave Steffen, Ph.D. "There are two ways to write error-free Software Engineer IV programs; only the third one works." Numerica Corporation ph (970) 419-8343 x27 "Pie are not square. Pie are round. fax (970) 223-6797 Cornbread are square" dgsteffen(a)numerica.us ... anon (usenet)

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boost::filesystem BUG !! (Windows XP)
by Saurabh Sood 01 Jul '05

01 Jul '05

Hi all, Input : dir_path \code boost::filesystem::path p(dir_path, boost::filesystem::native); boost::filesystem::directory_iterator i(p), j; while (i != j) { std::cout << i->string(); // Output ++i; } \endcode On Windows XP, If input dir_path is "d:\" , the i->string() returns complete path of all files and directories. BUT, If input dir_path is "d:" , the i->string() returns relative path of all files and directories. Please check if this is desired behaviour or not !! thanks saurabh

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