c++ - Efficiency of std::copy vs memcpy -

-

इस सवाल का पहले से ही एक उत्तर है: < / P>

  • 8 जवाब

    दक्षता कितना गंभीर है memcpy और std :: copy का उपयोग करने के बीच

    मेरे पास एक ऐसी स्थिति है जहां मेरे सिस्टम पर सदिश कार्यान्वयन परिसीमित स्मृति का उपयोग नहीं करता है, जो कि मुझे :: मेकपीपी (डिस्ट, और वीक [0], आकार) करने के बजाय इसकी सामग्री की प्रतिलिपि बनाना है; मुझे यकीन नहीं है कि यह कितनी बुरी तरह से दक्षता को प्रभावित करने की संभावना है।

    एक उचित सभ्य कार्यान्वयन होगा <

    यदि आपका कार्यान्वयन करता है तो कोड> std :: copy कॉल के लिए संकलित करें memmove उन स्थितियों में जहां यह संभव है (अर्थात तत्व प्रकार एक पीओडी है)।

    संगत भंडारण नहीं है (सी + 03 03 मानक की आवश्यकता है), memmove से std :: copy की तुलना में तेज़ हो सकता है, लेकिन शायद बहुत ज्यादा नहीं। मैं केवल तब ही चिंता करना शुरू कर दूँगा जब आपके पास मापने के लिए माप होना वास्तव में एक मुद्दा है।

Comments

Post a Comment

Popular posts from this blog

mysql - BLOB/TEXT column 'value' used in key specification without a key length -

-
I have developed an extension which works up to 1.6 on Magren (I'm trying Enterprise Edition, And I think the community is the same problem, because it is the same code). In my install script, I see the $ installer-> gt; CreateEntityTables ($ this- & gt; getTable ('alphanum / info')); The installation is done until it is not in the _text unit table. It crashed there! It turns out that when I log in to SQL and run it via PHPmyadmin, then this error is: Blob / Text column 'value' is used without the key 'key' . I saw the code there, and this is what is trying to create an index on the value column: -> addIndex ($ this- & gt; getIdxName ($ eavTableName, array ( 'attribute_id array (' attribute_id ',' value ')) - & gt; addIndex ($ this- & gt; getIdxName ($ eavTableName, array (' entity_type_id ' , 'Value')), array ('entity_type_id', 'value')) If there is no if statement is n...
Read more

c# - Using Vici cool Storage with monodroid -

-
Oh, for the moment I am not sure how it is officially supported, but for the success of the people Using Monodroid Vic Cool Storage I am able to leave and compile assemblies in my project, but while trying to use some classes, the errors of time have to be gathered. Especially when trying to connect like the example for Mono Touch string dbName = path. Cobain (environment. Gatefolder path (environment specialfolder personal), "mydb.db3"); // The following line will be called coolestation, where is the database, // to make it if it does not exist, and call a delegate that creates the necessary tables (only when the database file was newly created //) CSConfig.SetDB (DbName, true, () => {CSDatabase.ExecuteNonQuery ("Subscriber Integer Primary Key Attribute, Name Text (50) No, Number, Date First Text (30)");); There is no difference when I try to use the methods of CSConfig and when I cscfif If I try to pass 3 aggregates to STDB (3) then I get the invalid ...
Read more

python - referencing a variable in another function? -

-
I am an experienced TCL developer and write my own processes to help myself. I call it a proc i callVar, print out the value of the variable in a certain format, so I know that it is variable and what is the value "set foo 1; putVar foo" result 'foo = "1" I want to do the same thing in Python, but I can not find the answer :( In TCL I use the up command because when I pass the name of the variable, then I can see the value at the top. . I understand that an advanced light in the dragon There is no mechanism of r, but with its introspection capability, I would think that this is something trivial, but I am not getting the answer anywhere. It seems that this should work: and expanded: def foo (): y = "Hello World" printwor ("y") foo () y = "Hello World " You can, but you should not do so if your code is correct If is needed , then there is something wrong with your design, and you should probably use the dictionar...
Read more