c++ - error: invalid use of 'Config::testMap' -

-

here code:

#include <iostream> #include <string> #include <map> #include <stdexcept> #include <boost/ptr_container/ptr_vector.hpp>  struct teststruct {     std::string str1;     int var1; };  struct config {     // map     typedef std::map< std::string, boost::ptr_vector<struct teststruct> > testmap; };  void foo(config& config) {     if (config.testmap.empty())     {         std::cout << "it worked!" << std::endl;     }     else     {         std::cout << "it didn't work!" << std::endl;     }     return; }  int testmain(void) {     config config;      foo(config);      return; }  int main(void) {     try     {         return testmain(/*argc, argv*/);     }     catch(std::exception& err)     {         std::cerr << "error running program: " << err.what() << std::endl;         return 1;     }     catch(...)     {         std::cerr << "program failed unknown exception." << std::endl;         return 1;     } }

i'm new maps - never used 1 before. i've found many examples of how use them online. unfortunately can't seem makes sense of more advanced examples of them.

what i'd create map key (std::string) , value (boost::ptr_vector<struct>).

i going start declaring , passing around successfully. wanted try , figure out how fill up.

i ran error vague enough don't know how interpret it.

any suggestions on i've done wrong in "use" of testmap?

also, can provide simple example of how can populate map up.

say want key of a , value of str1 = "hello", var1 = 10. how this?

follow question: in regards answer left below kerrek sb.

if following...

std::string key   = "a"; teststruct value = {"hello", 10}; config.testmap[key] = value;

i following error:

 error: no match 'operator=' in 'config->config::testmap.std::map<_key, _tp, _compare, _alloc>::operator[] [with _key = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, _tp = boost::ptr_vector<teststruct, boost::heap_clone_allocator, std::allocator<void*> >, _compare = std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, _alloc = std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::ptr_vector<teststruct, boost::heap_clone_allocator, std::allocator<void*> > > >](((const std::basic_string<char, std::char_traits<char>, std::allocator<char> >&)((const std::basic_string<char, std::char_traits<char>, std::allocator<char> >*)(& key)))) = value' /usr/local/boost/boost_1_38_0_gcc4/include/boost/ptr_container/ptr_vector.hpp:45: note: candidates are: boost::ptr_vector<t, cloneallocator, allocator>& boost::ptr_vector<t, cloneallocator, allocator>::operator=(std::auto_ptr<boost::ptr_vector<t, cloneallocator, allocator> >) [with t = teststruct, cloneallocator = boost::heap_clone_allocator, allocator = std::allocator<void*>] /usr/local/boost/boost_1_38_0_gcc4/include/boost/ptr_container/ptr_vector.hpp:45: note:                 boost::ptr_vector<t, cloneallocator, allocator>& boost::ptr_vector<t, cloneallocator, allocator>::operator=(boost::ptr_vector<t, cloneallocator, allocator>) [with t = teststruct, cloneallocator = boost::heap_clone_allocator, allocator = std::allocator<void*>]

if instead .insert() method following error:

instantiated here /opt/csw/gcc4/lib/gcc/sparc-sun-solaris2.8/4.3.2/../../../../include/c++/4.3.2/bits/stl_pair.h:106: error: no matching function call 'boost::ptr_vector<teststruct, boost::heap_clone_allocator, std::allocator<void*> >::ptr_vector(const teststruct&)' /usr/local/boost/boost_1_38_0_gcc4/include/boost/ptr_container/ptr_vector.hpp:50: note: candidates are: boost::ptr_vector<t, cloneallocator, allocator>::ptr_vector(typename boost::ptr_sequence_adapter<t, std::vector<void*, allocator>, cloneallocator>::size_type, const typename boost::ptr_sequence_adapter<t, std::vector<void*, allocator>, cloneallocator>::allocator_type&) [with t = teststruct, cloneallocator = boost::heap_clone_allocator, allocator = std::allocator<void*>] /usr/local/boost/boost_1_38_0_gcc4/include/boost/ptr_container/ptr_vector.hpp:45: note:                 boost::ptr_vector<t, cloneallocator, allocator>::ptr_vector(std::auto_ptr<boost::ptr_vector<t, cloneallocator, allocator> >) [with t = teststruct, cloneallocator = boost::heap_clone_allocator, allocator = std::allocator<void*>] /usr/local/boost/boost_1_38_0_gcc4/include/boost/ptr_container/ptr_vector.hpp:45: note:                 boost::ptr_vector<t, cloneallocator, allocator>::ptr_vector(const typename boost::ptr_sequence_adapter<t, std::vector<void*, allocator>, cloneallocator>::allocator_type&) [with t = teststruct, cloneallocator = boost::heap_clone_allocator, allocator = std::allocator<void*>] /usr/local/boost/boost_1_38_0_gcc4/include/boost/ptr_container/ptr_vector.hpp:45: note:                 boost::ptr_vector<t, cloneallocator, allocator>::ptr_vector() [with t = teststruct, cloneallocator = boost::heap_clone_allocator, allocator = std::allocator<void*>] /usr/local/boost/boost_1_38_0_gcc4/include/boost/ptr_container/ptr_vector.hpp:35: note:                 boost::ptr_vector<teststruct, boost::heap_clone_allocator, std::allocator<void*> >::ptr_vector(const boost::ptr_vector<teststruct, boost::heap_clone_allocator, std::allocator<void*> >&)

follow up:

from i've researched not possible.

you cannot use ptr_vector in map. (so i've been told) due ownership/copy issues?

"what happens when attempt copy ptr_vector, bound happen inside map? pointer containers model exclusive ownership of pointers.

you can c++0x , std::move, won’t here."

can provide counter example?

your class config doesn't contain members! (just typedef.) define member, too:

struct config {     typedef std::map<std::string, boost::ptr_vector<teststruct> > testmap_type;      testmap_type testmap; // member };

also, in c++ there no need struct teststruct, teststruct.

to add element:

std::string key = "xxx"; teststruct  val = { "hello", 10 };  // insert []-operator config.testmap[key] = val;  // insert insert(): config.testmap.insert(std::pair<std::string, teststruct>(key, val)); // alternative

edit: sorry, misrepresented actual data structure. here's example std::vector:

typedef std::map<std::string, std::vector<int>> mymap; mymap m;  m["hello"].push_back(1); m["hello"].push_back(2); m["world"].push_back(3);

in case, config.testmap[key].push_back(val), or make new vector:

boost::ptr_vector<teststruct> new_v; // populate new_v; config.testmap.insert(std::pair<std::string, boost::ptr_vector<teststruct>>(key, new_v);

Comments

Post a Comment

Popular posts from this blog

c# - How to set Z index when using WPF DrawingContext? -

-
how set z-index drawing object when using drawingcontext.drawxxx() methods? the object drawn last have higher z index. can't change index of drawn objects. way draw in order. if using wpf (as placed tag), can use, example, canvas control. create shapes need like polyline obj = new polyline(); //... // ... set properties of obj and add them canvas uielementcollection: yourcanvasname.children.add(obj); //or yourcanvasname.children.insert(i, obj); first items of collection have higher z index. advantages in way: no need redraw on window changes, can anytime move objects , change order.
Read more

razor - Is this a bug in WebMatrix PageData? -

-
i think may have found bug in webmatrix's pagedata, not sure. concerns how pass data partial page calling page. in webmatrix documentation (tutorials, e.g. " 3 - creating consistent look ", , example code), pagedata recommended mechanism pass data between pages (e.g. content page layout page, or partial page). however have found not work other way, pass data partial page calling page. modifying or adding entries in pagedata in partial page, not seem calling page. cutting right down simplest possible example, in test page may have this: @{ pagedata["test"] = "initial entry"; } <p>before calling partial page, test value @pagedata["test"]</p> @renderpage("_testpartial.cshtml") <p>after returning calling page, test value @pagedata["test"]</p> and in _testpartial.cshtml page might have this: @{ pagedata["test"] = "modified entry"; } <p>in partial page...
Read more

visual c++ - Using relative values in array sorting ( asm ) -

-
i need sort through array , sort each individual row in array in ascending order. doesn't seem going (surprise!) keep getting hit 2 errors: a2101: cannot add 2 relocatable labels , a2026: constant expected here's sort, makes sense me, think i'm still trying implement high-lvl language techniqes assembly. there way around not being able use relative values? (the array 7 rows 9 columns, btw). mov cx, 7; cx = number of rows outer: ; outer loop walk through rows push cx mov cx, 9 mov row, cx ;rows middle: ; middle-loop walk through columns push cx sub cx, 1 ;cx = cx-1 mov column, cx ;columns inner: ;inner loop - compare , exchange column values cmp marray[row*9 + column], marray[row*9 + column+1] xchg marray[row*9 + column+1], marray[row*9 + column] ; compare , exchange values marray table inc column loop inner pop cx loop mid...
Read more