Why boost::bind insists pulling `boost::placeholders` into global namespace?











up vote
3
down vote

favorite












The following code can be fixed easily, but quite annoying.



#include <functional>

#include <boost/bind.hpp>

void foo() {

  using namespace std::placeholders;

  std::bind(_1, _2, _3); // ambiguous

}


There's a macro BOOST_BIND_NO_PLACEHOLDERS, but using this macro will also bring some drawbacks like causing boost::placeholders disappear from the compile unit included <boost/bind.hpp> but not included <boost/bind/placeholders.hpp>.



The name conflicts also comes with other libs like boost::mpl, I don't think the maintainers don't know the problem, but I want to know why they insist on not deprecating and deleting using namespace boost::placeholders in <boost/bind.hpp>.






c++ boost namespaces







share|improve this question






















  • I really think you should file a bug report and see how it goes. Best case scenario: it's fix. Bad case scenario : it's not fixed but you got a reason why. Worst case scenario: nothing happens.
    – YSC
    2 days ago










  • I think it has something to do with backwards compatibility. Back in the days when boost::bind was invented there was no constexpr and/or other technics. So they decided to put placeholders into global space. With the current standard it is possible to have them in an namespace. However, removing from global namespace would break a lot of code -> (ugly) workaround solution: using namespace boost::placeholders;.
    – user1810087
    2 days ago

















up vote
3
down vote

favorite












The following code can be fixed easily, but quite annoying.



#include <functional>

#include <boost/bind.hpp>

void foo() {

  using namespace std::placeholders;

  std::bind(_1, _2, _3); // ambiguous

}


There's a macro BOOST_BIND_NO_PLACEHOLDERS, but using this macro will also bring some drawbacks like causing boost::placeholders disappear from the compile unit included <boost/bind.hpp> but not included <boost/bind/placeholders.hpp>.



The name conflicts also comes with other libs like boost::mpl, I don't think the maintainers don't know the problem, but I want to know why they insist on not deprecating and deleting using namespace boost::placeholders in <boost/bind.hpp>.






c++ boost namespaces







share|improve this question






















  • I really think you should file a bug report and see how it goes. Best case scenario: it's fix. Bad case scenario : it's not fixed but you got a reason why. Worst case scenario: nothing happens.
    – YSC
    2 days ago










  • I think it has something to do with backwards compatibility. Back in the days when boost::bind was invented there was no constexpr and/or other technics. So they decided to put placeholders into global space. With the current standard it is possible to have them in an namespace. However, removing from global namespace would break a lot of code -> (ugly) workaround solution: using namespace boost::placeholders;.
    – user1810087
    2 days ago















up vote
3
down vote

favorite









up vote
3
down vote

favorite











The following code can be fixed easily, but quite annoying.



#include <functional>

#include <boost/bind.hpp>

void foo() {

  using namespace std::placeholders;

  std::bind(_1, _2, _3); // ambiguous

}


There's a macro BOOST_BIND_NO_PLACEHOLDERS, but using this macro will also bring some drawbacks like causing boost::placeholders disappear from the compile unit included <boost/bind.hpp> but not included <boost/bind/placeholders.hpp>.



The name conflicts also comes with other libs like boost::mpl, I don't think the maintainers don't know the problem, but I want to know why they insist on not deprecating and deleting using namespace boost::placeholders in <boost/bind.hpp>.






c++ boost namespaces







share|improve this question













The following code can be fixed easily, but quite annoying.



#include <functional>

#include <boost/bind.hpp>

void foo() {

  using namespace std::placeholders;

  std::bind(_1, _2, _3); // ambiguous

}


There's a macro BOOST_BIND_NO_PLACEHOLDERS, but using this macro will also bring some drawbacks like causing boost::placeholders disappear from the compile unit included <boost/bind.hpp> but not included <boost/bind/placeholders.hpp>.



The name conflicts also comes with other libs like boost::mpl, I don't think the maintainers don't know the problem, but I want to know why they insist on not deprecating and deleting using namespace boost::placeholders in <boost/bind.hpp>.






c++ boost namespaces




c++ boost namespaces






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 2 days ago









user2709407

958




958












  • I really think you should file a bug report and see how it goes. Best case scenario: it's fix. Bad case scenario : it's not fixed but you got a reason why. Worst case scenario: nothing happens.
    – YSC
    2 days ago










  • I think it has something to do with backwards compatibility. Back in the days when boost::bind was invented there was no constexpr and/or other technics. So they decided to put placeholders into global space. With the current standard it is possible to have them in an namespace. However, removing from global namespace would break a lot of code -> (ugly) workaround solution: using namespace boost::placeholders;.
    – user1810087
    2 days ago




















  • I really think you should file a bug report and see how it goes. Best case scenario: it's fix. Bad case scenario : it's not fixed but you got a reason why. Worst case scenario: nothing happens.
    – YSC
    2 days ago










  • I think it has something to do with backwards compatibility. Back in the days when boost::bind was invented there was no constexpr and/or other technics. So they decided to put placeholders into global space. With the current standard it is possible to have them in an namespace. However, removing from global namespace would break a lot of code -> (ugly) workaround solution: using namespace boost::placeholders;.
    – user1810087
    2 days ago


















I really think you should file a bug report and see how it goes. Best case scenario: it's fix. Bad case scenario : it's not fixed but you got a reason why. Worst case scenario: nothing happens.
– YSC
2 days ago




I really think you should file a bug report and see how it goes. Best case scenario: it's fix. Bad case scenario : it's not fixed but you got a reason why. Worst case scenario: nothing happens.
– YSC
2 days ago












I think it has something to do with backwards compatibility. Back in the days when boost::bind was invented there was no constexpr and/or other technics. So they decided to put placeholders into global space. With the current standard it is possible to have them in an namespace. However, removing from global namespace would break a lot of code -> (ugly) workaround solution: using namespace boost::placeholders;.
– user1810087
2 days ago






I think it has something to do with backwards compatibility. Back in the days when boost::bind was invented there was no constexpr and/or other technics. So they decided to put placeholders into global space. With the current standard it is possible to have them in an namespace. However, removing from global namespace would break a lot of code -> (ugly) workaround solution: using namespace boost::placeholders;.
– user1810087
2 days ago



















active

oldest

votes











Your Answer






StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














 

draft saved


draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53203970%2fwhy-boostbind-insists-pulling-boostplaceholders-into-global-namespace%23new-answer', 'question_page');
}
);

Post as a guest























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















 

draft saved


draft discarded



















































 


draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53203970%2fwhy-boostbind-insists-pulling-boostplaceholders-into-global-namespace%23new-answer', 'question_page');
}
);

Post as a guest






































































-

Popular posts from this blog

Guess what letter conforming each word

Image
6 $begingroup$ This is an entry in the Fortnightly Topic Challenge #41: Short and Sweet. 1 letter only could be mean anything . With an additional letter in front , could be used as medicine component and something you definitely learn or at least heard once. Add another letter in front , you would possibly hear that many times . Add an additional letter in front , you would found an independent country . With an additional letter, in the end , you would found something related to apple . Add another letter in the end , you would found something bad . Hint: Each letter is unique . word knowledge letters chemistry share | improve this question ...
Read more

Port of Spain

Image
For ports in the country of Spain, see List of ports in Spain. City in City of Port of Spain, Trinidad and Tobago Port of Spain City City of Port of Spain Top to bottom (left to right): Skyline of Port of Spain from Gulf of Paria; National Academy for the Performing Arts, Independence Square, Eric Williams Plaza; MovieTowne, Port of Port of Spain Motto(s):  "We Gather Strength As We Go Along" Port of Spain Coordinates: 10°40′N 61°31′W  /  10.667°N 61.517°W  / 10.667; -61.517 Coordinates: 10°40′N 61°31′W  /  10.667°N 61.517°W  / 10.667; -61.517 Country   Trinidad and Tobago Jurisdiction City of Port of Spain Settled 1560 Incorporated (town) 1853 Incorporated (city) 1914 Government  • Mayor Joel Martinez  • Governing body City Corporation Area [1]  • City 12 km 2 (5 sq mi) Elevation [2] 66 m (217 ft) Population (2011) [1]  • City 37,074  • Rank 3rd  • Density 3,090/km 2 (8,000/sq mi)...
Read more

Run scheduled task as local user group (not BUILTIN)

Image
0 I am trying to run a scheduled task with User Group (not a single user). This is working fine when I in the field "when running a task, use the following user account:" insert BUILTIN User Group (for example: Administrators or Users). But when I try it with the created Local User Group (example: TestGroup) it is not working. The Users in the TestGroup are the same as in the Administrators group. What could be the problem? Are there some restrictions to the Created User Group compared to BUILTINUsers? scheduled-tasks taskscheduler windowstaskschedule share | improve this question asked Nov 15 '18 at 15:36 Far...
Read more