std::map<Str8, int>.find() behaviour

takashi · 06-22-2016 03:05 AM

Hi,

I found std::map<Str8, int>.find() doesn't work properly.

* In case of std::string
-------------------------------
typedef std::map<std::string, int> CueMap;
CueMap _cueMap;

std::string key = cueName;
_cueMap.insert( std::make_pair( key, grpNo ) );
CueMap::iterator it = _cueMap.find(key); // FOUND
-------------------------------

* In case of Str8
-------------------------------
typedef std::map<Str8, int> CueMap;
CueMap _cueMap;

Str8 key = cueName;
_cueMap.insert( std::make_pair( key, grpNo ) );
CueMap::iterator it = _cueMap.find(key); // NOT FOUND!!
-------------------------------

I suppose Str8's compare operator is not implemented properly.
Is it expected behaviour?

Thanks,
Takashi

**Esenthel** · 06-22-2016 05:27 AM

Hello,

I never use std::map so I don't know.

I use EE::Map, and EE::Compare functions to compare strings.

takashi · 06-22-2016 07:03 AM

Hi,

(06-22-2016 05:27 AM)Esenthel Wrote: Hello,

I never use std::map so I don't know.

I use EE::Map, and EE::Compare functions to compare strings.

EE::Map has no iterator, doesn't it?
In addition, I want to get key and value pair like std::pair.

Or should I use std::map<std::string, int> instead?

Thanks,
Takashi

**Esenthel** · 06-22-2016 09:49 AM

I recommend using these methods:

Code:

void   lock      (            )C; //   lock      elements          container, unlock must be called after locking container

 C KEY &  lockedKey (  Int   i   )C; // access i-th element key  from container, this   can  be used   after locking and before unlocking the container

   DATA&  lockedData(  Int   i   ) ; // access i-th element data from container, this   can  be used   after locking and before unlocking the container

 C DATA&  lockedData(  Int   i   )C; // access i-th element data from container, this   can  be used   after locking and before unlocking the container

   void unlock      (            )C; // unlock      elements          container, this   must be called after locking the container

http://www.esenthel.com/?id=doc#API/Memory/Map

takashi · 06-22-2016 10:42 AM

I'm afraid that the lock is slow and might cause performance issue.

Zervox · 06-22-2016 02:07 PM

Have you performance profiled it to see if it actually is an issue?

**Esenthel** · 06-22-2016 03:18 PM

The 'lock' and 'unlock' are optional, and don't need to be called, as long as you will call 'Map' methods only on one thread at the same time.

takashi · 06-23-2016 07:26 AM

(06-22-2016 03:18 PM)Esenthel Wrote: The 'lock' and 'unlock' are optional, and don't need to be called, as long as you will call 'Map' methods only on one thread at the same time.

OK. I'll use lockedData.
Thanks a lot!

std::map<Str8, int>.find() behaviour
Author	Message