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error_code using c++11 and boost
by Lars 07 Dec '18

07 Dec '18

Hello, A project that uses Boost 1.6X (filesystem, uuid, asio) and C++14 on multiplatform. Does it make sense to use std::error_code in this project ? The concern is compatibility between boost and std. The filesystem_error exception will return a boost ::system::error_code which is not compatible with std::error_code as far as I can tell. Exception is not an option. Would it be possible for boost to implement some sort of convertion method from boost::system::error_code to std::errror_code? Thanks kind regards, Lars

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Re: [Boost-users] error_code using c++11 and boost
by Bjorn Reese 06 Dec '18

06 Dec '18

On 11/16/18 4:06 PM, Lars via Boost-users wrote: > Would it be possible for boost to implement some sort of convertion > method from boost::system::error_code to std::errror_code? The upcoming 1.69 release of Boost.System has built-in support for std::error_code. If you need to use earlier versions, then you can create a bridge between the two: http://breese.github.io/2016/06/18/unifying-error-codes.html

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[Spirit] How to prohibit reserved names from matching
by Michael Powell 06 Dec '18

06 Dec '18

Hello, Let's say I have some Qi rules: qi::rule<It, char()> mych; qi::rule<It, std::string()> myname; struct reserved_names_t : qi::symbols<path_t, path_t> { reserved_names_t() { this->add("CON", "CON") ("PRN", "PRN") ("AUX", "AUX") ("NUL", "NUL") ("COM1", "COM1") ("COM2", "COM2") ("COM3", "COM3") ("COM4", "COM4") ("COM5", "COM5") ("COM6", "COM6") ("COM7", "COM7") ("COM8", "COM8") ("COM9", "COM9") ("LPT1", "LPT1") ("LPT2", "LPT2") ("LPT3", "LPT3") ("LPT4", "LPT4") ("LPT5", "LPT5") ("LPT6", "LPT6") ("LPT7", "LPT7") ("LPT8", "LPT8") ("LPT9", "LPT9") ; } } reserved_names; Assuming I've defined mych accordingly, the simple approach would be: myname %= +myname; This gets me the name in the character set. Now, I want to prohibit the reserved names from matching. myname %= ~qi::no_case[reserved_names] | +myname; However, this does not seem to work. I suppose it is one thing ruling out invalid characters, but what about prohibiting whole strings? Thanks in advance for any insights... Michael Powell

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LLVM bitcode for Boost libraries?
by Osman Zakir 06 Dec '18

06 Dec '18

I want to build a project I have, which has to link against Boost.System, to WebAssembly, and it seems like I have to generate LLVM bitcode for it first. Is it possible to use the bootstrapper that comes with the Boost distribution to do this on Windows 10? The project in question is on GitHub here: https://github.com/DragonOsman/currency_converter . I switched out the Asio in the Boost distribution with the official Emscripten port of Asio, found here: https://github.com/emscripten-ports/asio . But I don't know which version of Boost.Asio it's using so I'd like some clarification on that if possible (I opened this issue there: https://github.com/emscripten-ports/asio/issues/2 and have just now updated the question to ask what version of Asio is being used for the port). [https://avatars0.githubusercontent.com/u/18173932?s=400&v=4]<https://github.com/emscripten-ports/asio/issues/2> Update of Asio port? · Issue #2 · emscripten-ports/asio<https://github.com/emscripten-ports/asio/issues/2> Sorry if this is an unwelcome question, but I want to ask if there'll ever be an update to this port of Asio to Emscripten/WebAssembly. I notice it's from 2015. Which version of Boost is it... github.com [https://avatars1.githubusercontent.com/u/8116924?s=400&v=4]<https://github.com/emscripten-ports/asio> GitHub - emscripten-ports/asio<https://github.com/emscripten-ports/asio> Join GitHub today. GitHub is home to over 28 million developers working together to host and review code, manage projects, and build software together. github.com [https://avatars0.githubusercontent.com/u/18173932?s=400&v=4]<https://github.com/DragonOsman/currency_converter> GitHub - DragonOsman/currency_converter: Application for Computer Science course<https://github.com/DragonOsman/currency_converter> Google Maps + Currency Converter Web Application. Application for Computer Science course. This is a currency converter web application with the frontend and a backend. github.com

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Boost.Beast vs Boost.Asio
by Cristian Morales Vega 04 Dec '18

04 Dec '18

There are lots of things which I would expect to be in Boost.Asio which are actually in Boost.Beast. Why? Most of it is "helping" code/docs. For example: - Documentation about (and public interfaces to simplify) the creation of composed operations https://www.boost.org/doc/libs/develop/libs/beast/doc/html/beast/using_io/w… - beast::buffers_cat - beast::test::stream (to be fair, it's in experimental) But now we even have code to work around issues in Boost.Asio which ideally would simply be fixed in Boost.Asio. For example: beast::ssl_stream. I'm personally using all of the above, they are extremely useful. I just supposed it is because there is only one person working on Boost.Asio, and Christopher must be quite busy with life and getting Networking TS into the standard. I was hoping all this would go away by 2020 and I was ignoring the issue. But since now it seems Networking TS will have to wait for 2023... well, I am asking myself how to handle an increasing amount of references to Beast that in a future could change to Asio (potentially with slightly different names/semantics). So I am writing this hoping for some light on the situation.

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Re: [Boost-users] [asio] UDP recv error handling
by Bjorn Reese 03 Dec '18

03 Dec '18

On 11/22/18 3:44 PM, Klebsch, Mario via Boost-users wrote: > Are there any recommendations on how to decide, whether the receive > callback function should re-initiate a receive operation after a receive > error or not? Unlike TCP, UDP does not establish a connection. By default you will not receive any network errors on a UDP socket. You have to call connect() on the socket in order to receive (ICMP) error messages, but this has other implications. With UDP it is more common to rely on application layer error messages and/or timeouts.

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Monitor OSX kqueue descriptor for events with ASIO
by Blaine Walls 02 Dec '18

02 Dec '18

Hi all, I'm using boost::asio on OS X. I'd like to watch for changes to a particular regular file - per Apple's documentation, the preferred method for this is with the kevent API. So I do the following: 1) Wrap a kqueue file descriptor (obtained via a call to kqueue()) in a boost::asio::posix::stream_descriptor with boost::asio::posix::stream_descriptor::assign(). 2) Call boost::asio::posix::stream_descriptor::async_wait() to be notified of file events. The problem appears to be that boost::asio::posix::stream_descriptor::async_wait() uses ioctl() w/ FIONBIO to put the file into non-blocking mode, which fails with "Inappropriate ioctl for device". A normal blocking call to wait() works just fine. I realize that my problem is that the kqueue descriptor does not represent a stream of bytes, so it's probably invalid to use stream_descriptor to wrap it. Does anyone have any ideas on how to work around this? I looked for a type concept for a non-stream descriptor that I could implement, but I didn't see anything obvious. Thanks in advance for any advice, -Blaine

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boost/units - converting forces (lbf->N)
by Matt Vinson 01 Dec '18

01 Dec '18

To see if I understand the library, I want to create metric and imperial systems without using Boost Units predefined systems*. Conversions between lengths are going well. Conversion between forces are going well until pounds-force to newtons; line 182 in the link. What am I doing wrong when lbf will not convert to newtons? Here is my code: https://coliru.stacked-crooked.com/a/f5f80d39fbdf8013 Any help is appreciated. * //imperial namespace boost {namespace units { namespace us {}}}//sinamespace boost { namespace units { namespace si {}}}

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Boost on Android-ndk
by Philip_liu 30 Nov '18

30 Nov '18

Hi everyone, I want to build a boost on android-ndk in ubuntu18.04,I had tried boost 1.58 and 1.68 on android-ndk r10e r13b r15c,and all failed at the step "./b2 \"with error"version 'xx' of default 'g++' does not match".Hope to know how to solve the problem or tell me how to install successfully with the right version in ubuntu18.04. Best Regard, Philip Liu

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[Spirit] Qi Symbols mapping to AST enum
by Michael Powell 28 Nov '18

28 Nov '18

Hello, I've got a qi::symbols capturing some built-in types. At the moment, I gather, they are mapped to std::string. However, I would rather map them to an AST level enum. For instance, struct builtin_type_t : qi::symbols<char, std::string> { builtin_type_t() { this->add("double", "double") ("float", "float") // ... ; } } builtin_type; Instead, namespace ast { enum type_t { type_double, type_float /* , ... */ }; } struct builtin_type_t : qi::symbols<char, ast::type_t> { builtin_type_t() { this->add("double", ast::type_double) ("float", ast::type_float) // ... ; } } builtin_type; I assume this is possible? Am I missing something about that? Thanks! Michael Powell

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