Click here to Skip to main content
14,698,687 members
Home » Discussions » ATL / WTL / STL
   

ATL / WTL / STL

 
QuestionWhy does this fail - CFile / SeekToEnd? Pin
charlieg10-Oct-12 7:43
Membercharlieg10-Oct-12 7:43 
AnswerRe: Why does this fail - CFile / SeekToEnd? Pin
charlieg10-Oct-12 10:31
Membercharlieg10-Oct-12 10:31 
AnswerRe: Why does this fail - CFile / SeekToEnd? Pin
chaau10-Oct-12 12:23
Memberchaau10-Oct-12 12:23 
GeneralRe: Why does this fail - CFile / SeekToEnd? Pin
charlieg11-Oct-12 3:20
Membercharlieg11-Oct-12 3:20 
AnswerRe: Why does this fail - CFile / SeekToEnd? Pin
Richard MacCutchan10-Oct-12 22:45
mveRichard MacCutchan10-Oct-12 22:45 
GeneralRe: Why does this fail - CFile / SeekToEnd? Pin
charlieg11-Oct-12 3:30
Membercharlieg11-Oct-12 3:30 
GeneralRe: Why does this fail - CFile / SeekToEnd? Pin
charlieg11-Oct-12 5:53
Membercharlieg11-Oct-12 5:53 
GeneralRe: Why does this fail - CFile / SeekToEnd? Pin
Richard MacCutchan11-Oct-12 12:19
mveRichard MacCutchan11-Oct-12 12:19 
GeneralRe: Why does this fail - CFile / SeekToEnd? Pin
charlieg11-Oct-12 12:34
Membercharlieg11-Oct-12 12:34 
GeneralRe: Why does this fail - CFile / SeekToEnd? Pin
Richard MacCutchan11-Oct-12 13:01
mveRichard MacCutchan11-Oct-12 13:01 
GeneralRe: Why does this fail - CFile / SeekToEnd? Pin
charlieg12-Oct-12 6:54
Membercharlieg12-Oct-12 6:54 
AnswerRe: Why does this fail - CFile / SeekToEnd? Pin
Stephen Hewitt11-Oct-12 13:58
MemberStephen Hewitt11-Oct-12 13:58 
AnswerRe: Why does this fail - CFile / SeekToEnd? Pin
charlieg18-Jan-13 2:47
Membercharlieg18-Jan-13 2:47 
QuestionKeep program open and running Pin
Lucidation8-Oct-12 12:23
MemberLucidation8-Oct-12 12:23 
AnswerRe: Keep program open and running Pin
Richard MacCutchan8-Oct-12 23:14
mveRichard MacCutchan8-Oct-12 23:14 
GeneralRe: Keep program open and running Pin
Lucidation9-Oct-12 12:14
MemberLucidation9-Oct-12 12:14 
GeneralRe: Keep program open and running Pin
Richard MacCutchan9-Oct-12 12:19
mveRichard MacCutchan9-Oct-12 12:19 
AnswerRe: Keep program open and running Pin
Stephen Hewitt11-Oct-12 22:45
MemberStephen Hewitt11-Oct-12 22:45 
QuestionUSBView Compile Error Pin
Jim Fell5-Oct-12 11:17
MemberJim Fell5-Oct-12 11:17 
AnswerRe: USBView Compile Error Pin
Wes Aday5-Oct-12 11:33
professionalWes Aday5-Oct-12 11:33 
GeneralRe: USBView Compile Error Pin
Jim Fell10-Oct-12 9:04
MemberJim Fell10-Oct-12 9:04 
QuestionFree memory allocated by std::multimap Pin
MrKBA4-Oct-12 3:41
MemberMrKBA4-Oct-12 3:41 
AnswerRe: Free memory allocated by std::multimap Pin
xenotron6-Oct-12 16:26
Memberxenotron6-Oct-12 16:26 
It might depend on the implementation of the multimap. I checked it long ago but if I remember right your erase() call sets back the allocation to a minimum, identical to the allocation performed by the default ctor of multimap (at least in the SGI stl implementation of Visual C++ I used at the time). Note that even newly created empty std containers have a small piece of memory preallocated and some containers (like std::vector) dont shrink the size of the allocated memory area (capacity) even if you erase items.

A trick that seems to reset the allocated memory of any std containers regardless of stl implementation and container type is the following:
typedef std::multimap<int,int> MyMap;
MyMap global_map;

void my_func()
{
    // We create a new map instance and we swap its contents with the other "big" container instance.
    // This swap operation replaces the pointers inside the two containers so after the swap() the
    // global_map contains the small newly allocated blocks, and empty_map contains the big mem blocks
    // previously owned by global_map. Note: when empty_map runs out of scope it releases the big block.
    // This trick works with other stl container types too.
    MyMap empty_map;
    empty_map.swap(global_map);
}

AnswerRe: Free memory allocated by std::multimap Pin
Stephen Hewitt11-Oct-12 22:53
MemberStephen Hewitt11-Oct-12 22:53 
GeneralRe: Free memory allocated by std::multimap Pin
xenotron11-Oct-12 23:53
Memberxenotron11-Oct-12 23:53 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.