I have STL file where I want to apply 4x4 matrix. The matrix I want to apply is: [[2.7282, 0, 0, 0], [0, 4.0014, 0, 0], [0, 0, 1, 0], [0,�0,�0,�1]] Here is my STL file: https://we.tl/t-v6SHprAeUZ[^] I have used Python code to apply matrix...

STL

Matrix

Facing memory issue in class templates

20 May 2023 by steveb

clear() in STL containers does not re-shrink the allocated storage. If you call capacity(), you will get the real allocated storage size on an emptied container. If you must release the allocated storage you would need to call swap() function...

C++98

C++

STL

Facing memory issue in class templates

20 May 2023 by Mathi Prasad

Hi Team, i have tries to analysis the memcheck throughout while insertion of new elements in list, map, vector anything. am getting high memory utilization at particular PID in linux. After the list object as clearing, still am seeing the same...

C++98

C++

STL

Facing memory issue in class templates

18 May 2023 by CPallini

See, for instance: https://stackoverflow.com/questions/12050777/how-to-return-memory-from-process-to-the-os[^]

C++98

C++

STL

Facing memory issue in class templates

18 May 2023 by OriginalGriff

What did you expect? You are creating 10,000,000 streams, and adding them all to a list: list l1; for(int i=0;i

C++98

C++

STL

Need web site for STL containers memory allocation concept explain

4 Apr 2023 by Richard MacCutchan

Or you could go to Containers library - cppreference.com[^].

STL

Need web site for STL containers memory allocation concept explain

4 Apr 2023 by mathiv327

Hi friends, need website for STL containers about i needs to learn the memory allocation for different containers. please share that wenb site. What I have tried: have tried and learn some of web site but no use of it

STL

Need web site for STL containers memory allocation concept explain

4 Apr 2023 by OriginalGriff

Start with Google: website for STL containers - Google Search[^]

STL

Getting segmentation falut while using this STL?

20 Mar 2023 by mathiv327

Hi friends, am getting core while dereference the list iterator. Hence, i required condition for not executing this lines. I have tried using list empty and size also. but it was no use of it. #include #include using...

C++

STL

Getting segmentation falut while using this STL?

20 Mar 2023 by Daniel Pfeffer

it4 points to the beginning of the list 'itr2->second'. You then check whether 'itr2->second' is empty, and if it is, you attempt to dereference it4. If 'itr2->second' is empty, it4 cannot be dereferenced. Rewrite your code to invert the...

C++

STL

Array-Based Memory Pool and Allocator

6 Feb 2023 by Vadim Stadnik

Simple and useful alternative to traditional memory pool

How to generate a .gcode with programming for 3D printing

4 Jan 2023 by Yago.bg.

Original Subject line: Como generar un .gcode con programación para impresión 3D Necesito poder generar un .gcode a partir de un STL desde algún lenguaje de programación. Para poder imprimir en Impresoras 3D. Google translate: I need to be...

Python3.6

STL

How to generate a .gcode with programming for 3D printing

4 Jan 2023 by OriginalGriff

Ultimaker Cura is a commercial product (and a good one, I use it myself for FDM printing), so the libraries are almost certainly Ultimaker IP and not in the public domain. To acquire them, you would have to talk directly to Ultimaker and ask them...

Python3.6

STL

LINQ and Performance

15 Nov 2022 by Steffen Ploetz

Is LINQ the right technology for processing large amounts of data in runtime-relevant environments?

Cajoling std::chrono Operations to Link On the Teensy platform

24 Aug 2022 by honey the codewitch

std::chrono doesn't work on the Teensy? Oh no! Here's how to fix it.

Porting a Large Project from Windows to Linux

7 Jul 2022 by Greg Utas

Analogous functions, subtle differences, multiple compilers...

An Efficient String to Unsigned int ID Struct

22 Jun 2022 by Stephane Capo

C++ optimization for map using string key among others

Populating a std::list within a struct in C++

22 May 2022 by dj4400

Hi I am writing an app. in c++ that manages a list of polygons Each polygon contains a list of points The point is defined as follows: typedef struct { float x; float y; float z; }PolygonPoint; The Polygon is defined as follows: typedef...

C++

STL

Populating a std::list within a struct in C++

22 May 2022 by 0x01AA

Same here, ran the code without problems on https://www.onlinegdb.com/online_c++_compiler[^] /****************************************************************************** Online C++ Compiler. ...

C++

STL

Populating a std::list within a struct in C++

22 May 2022 by Richard MacCutchan

I just ran this code and it worked OK: std::list Polygons; //I declare a polygon: PolygonData stPol; stPol.id = 1; strcpy(stPol.name, "Foo"); PolygonPoint ppt; ppt.x = 1; ppt.y = 1; ppt.z = 1; stPol.PointsList.push_back(ppt); ...

C++

STL

Clone Smart Pointer (clone_ptr)

20 Jul 2021 by Axter

A smart pointer which acts like a reference variable

C++

STL

Visual-Studio

How do I access second element of a pair nested in another pair in stl?

9 Jun 2021 by Member 12621273

I have a vector like this : vector > > vI want to access all the three elements . How can i do that through iterator?What I have tried:I looked for the possible answers on the internet but cannot get any satisfactory answer. I tried iterator like this...

C++

STL

How do I access second element of a pair nested in another pair in stl?

9 Jun 2021 by merano99

// I have a vector like this : vector > > v; // I want to access all the three elements.How can i do that through iterator ? pair p1(1,2); pair > p2(3, p1); v.push_back(p2); ...

C++

STL

How do I access second element of a pair nested in another pair in stl?

9 Jun 2021 by Member 15239417

you do like this, vector > > v; INSERION OF VALUES: v.push_back(make_pair(a, make_pair(b, c))); ACCESSING VALUES: a = v[i].first; b = v[i].second.first; c = v[i].second.second;

C++

STL

STL: Amazing Speed Differences between std::vector and std::set (Observed with an UndoRedoAction).

2 Jun 2021 by Steffen Ploetz

Why replacing std::vector with std::set sped up my UndoRedoAction class by about 20x

C++

STL

Avoid the “std 2-step”

27 May 2021 by John M. Dlugosz

Using swap etc. from generic code must be done properly. Here’s how to fix it for good.

ToolBoxCtrl

14 Apr 2021 by Aleh Baradzenka

The control representing a regular ToolBar in the form of a tree of command buttons

How to access the outer most structure test member using map variable mapoftest2? I need to access the structure variable using map object.

24 Jan 2021 by CPallini

Here you are, but... Are you really sure you want this? #include #include using namespace std; struct Test { string name; int id; }; struct Test1 { int errCode; string errName; map mapOfTest; }; struct...

C++

STL

How to access the outer most structure test member using map variable mapoftest2? I need to access the structure variable using map object.

24 Jan 2021 by Member 15025528

I have below code. I have inserted the data in the structures. I need to access the first value of mapOfTest using mapOfTest2. #include #include using namespace std; typedef struct { string name; int id; }Test; ...

C++

STL

How to access the outer most structure test member using map variable mapoftest2? I need to access the structure variable using map object.

24 Jan 2021 by Richard MacCutchan

The variable mapOfTest2 contains an entry that points to a Test2 object. That in turn has an entry that points to a Test1 object. The Test1 object contains the mapOfTest map. So following the links will get you to that map and give access to its...

C++

STL

VC++ / STL question. Practical consequence of deprecate

23 Dec 2020 by Haakon S.

Hi. What does it mean when something is deprecated in STL. I understand that it is not recommended for use, but will it not be functioning anymore? I have previously used strstream in my application, pre 2012. In Visual Studio 2019 it does not...

C++

STL

VC++ / STL question. Practical consequence of deprecate

23 Dec 2020 by Richard MacCutchan

This is referring to your question at std:strstream does not work - C / C++ / MFC Discussion Boards[^]. When a method or class is deprecated, it means that it is not recommended and may be removed in the future. So if you have such references in...

C++

STL

How do I make an unordered_map type have itself as a value? (C++)

11 Dec 2020 by honey the codewitch

Apparently I'm getting rusty. I need to find a way to have an unordered_map reference a struct using just its forward declaration, but I want STL to handle allocation and cleanup like normal. See the code for a concrete example of what I want. ...

C++11

GCC

STL

How do I make an unordered_map type have itself as a value? (C++)

11 Dec 2020 by steveb

Forward declarations work only for pointers and references. Depending which compiler you using, the "map_value" is an incomplete type at the point where you declared it inside the struct map_value body. I beleive it probably should be: struct...

C++11

GCC

STL

How do I make an unordered_map type have itself as a value? (C++)

10 Dec 2020 by honey the codewitch

Try mv.value.insert(std::make_pair("test",std::unique_ptr(pmv2))). std::make_unique is really simply... dynamic allocation (with new) following by constructing a std::unique_ptr to hold the pointer. The constructor is explicit so it...

C++11

GCC

STL

Simple Approach to Voronoi Diagrams

18 Nov 2020 by Vadim Stadnik

Discussion of simple variants of Voronoi diagram

What is the time complexity of accumulate function in C++ STL for n integer vector?

11 Nov 2020 by Member 14849246

I was solving a problem of arrray of finding the pivot index of the array, ie. left sum and right sum of that element should be equal I used accumulate in stl but i wonder if interviewer ask the time complexity of the accumulate fx then i shoul...

C++14

C++

STL

What is the time complexity of accumulate function in C++ STL for n integer vector?

11 Nov 2020 by CPallini

It is O(N), of course.

C++14

C++

STL

What is the time complexity of accumulate function in C++ STL for n integer vector?

11 Nov 2020 by Rick York

Did your search find this page : accumulate - C++ Reference[^] ?

C++14

C++

STL

Concept Requires C++ 20

18 Oct 2020 by Espen Harlinn

An introduction to C++ 20 concepts

An Introduction to the Range-v3 Library

17 Aug 2020 by Espen Harlinn

Ranges is coming to C++, and the Range-v3 library was the basis for the proposal to add range support to the C++ standard library

Pls help! ! Must be done by sunday! ! !

4 Jun 2020 by Maciej Los

I'd suggest to start by reading tutorials: C++ Classes and Objects - GeeksforGeeks[^] Arrays in C/C++ - GeeksforGeeks[^] Inheritance in C++ - GeeksforGeeks[^] Polymorphism in C++ - GeeksforGeeks[^] Tip: under the third link, you'll find sample...

C++

STL

Pls help! ! Must be done by sunday! ! !

4 Jun 2020 by Patrice T

You show no attempt to solve the problem yourself, you have no question, your main effort is pasting the requirement, you just want us to do your HomeWork. We do not do your HomeWork. HomeWork is not set to test your skills at begging other...

C++

STL

Pls help! ! Must be done by sunday! ! !

4 Jun 2020 by CPallini

Find a suitable data structure. That is find for each car what are the relevent properties. Find a way to store to such a (an array of) structure (and then read back from) a file. Eventually implement all the required functionalities. If you are...

C++

STL

Pls help! ! Must be done by sunday! ! !

4 Jun 2020 by OriginalGriff

We are more than willing to help those that are stuck: but that doesn't mean that we are here to do it all for you! We can't do all the work, you are either getting paid for this, or it's part of your grades and it wouldn't be at all fair for us...

C++

STL

A Monitored, Memory Mapped std::allocator for Mass Data Storage in STL Container

26 May 2020 by stefan stammberger

A novel allocator implementation for managing huge sets of data in STL's std:: containers for Windows operating systems

An Efficient Parallel Three-Way Quicksort Using Intel C++ Compiler And OpenMP 4.5 Library

6 May 2020 by Arthur V. Ratz

In this article, I’d like to introduce the modern code in C++11, implementing the parallel three-way quicksort, which is asymptotically faster and more efficient than the famous heapsort and mergesort algorithms.

Top 5 Lessons for Software Development Team Leads

19 Mar 2020 by Nikola M. Živković

In this article I tried to sum up what has been my greatest challenges and things that I had to accept and change about myself after becoming Team Lead.

STL

KeePass Password Safe

13 Jan 2020 by Dominik Reichl

KeePass is a free, open source, light-weight and easy-to-use password manager.

CString and std::string Integration

19 Dec 2019 by Edwig Huisman

CString only projects can convert to STL std::string

Numerical Methods with C++ Part 4: Introduction Into Decomposition Methods of Linear Equation Systems

3 Dec 2019 by thoughts-on-coding

Matrices are a key concept in solving linear equation systems. Efficient implementations of matrices are not only considering computation complexity but also space complexity of the matrix data.

A Set of Swift Standard Library Classes Equivalent to Some C++ STL Classes

23 Nov 2019 by Zhaohui Xing (Joey)

Swift classes for algorithm, including single linked list class, stack class, queue class

What is an easy game to code in C++ that can be used with STL's hashes, sets, and maps data structures?

29 Oct 2019 by SelfTask

What is an easy game to code in C++ that uses with STL's hashes, sets, and maps data structures? What I have tried: I was thinking War or Blackjack but what's a better idea outside card games?

What is an easy game to code in C++ that can be used with STL's hashes, sets, and maps data structures?

29 Oct 2019 by John M. Dlugosz

I recall this series of videos on YouTube: Let's make 16 games in C++/SFML! - YouTube[^] There is also this series from OneLoneCoder: Code-It-Yourself! - YouTube[^]

WinLamb: using C++11 Lambdas to Handle Win32 Messages

22 Sep 2019 by Rodrigo Cesar de Freitas Dias

Introducing WinLamb, a modern C++11 object-oriented library to write native Windows programs

Multi-hashing

9 Apr 2019 by Martin Vorbrodt

Multi-hashing

C++

STL

Weekly Knowledge Candy

21 Mar 2019 by thoughts-on-coding

How can we share and increase software development knowledge in a heterogeneous team? Weekly Knowledge Candy

C++

PowerPoint

STL

Parsing Command Line Options

21 Mar 2019 by Martin Vorbrodt

Parsing Command Line Options

C++

Boost

STL

Serialize Data to XML

14 Mar 2019 by Martin Vorbrodt

How to serialize data to XML

Parallel STL

14 Mar 2019 by Martin Vorbrodt

Parallel STL

C++

STL

Using Pointer to Members on STL Algorithms

14 Mar 2019 by thoughts-on-coding

Using pointer to members is sometimes a mighty feature of C++. In this post you see a way of how to use them in STL algorithms.

C++

STL

My God, It’s Full of Stars: Implementing the Implicit Euler-Method with STL

14 Mar 2019 by thoughts-on-coding

Implementing the implicit Euler-Method with STL

STL

Sci-Fi Plot Compiler

19 Feb 2019 by steveb

A simple Sci-Fi plot compiler

C++ universal-signature delegates

4 Feb 2019 by Timothy Hogan

In my embedded program I have a 5 "soft keys" arranged with a LCD screen. What I would like is to have a pointer for each button that can point to free functions or member functions and can take any signature. This pointer will need to be redirected to other functions at runtime. Obviously I...

STL

delegates

C++ universal-signature delegates

4 Feb 2019 by CPallini

As far as know, without considering 'dirty hacks' (trying to defeat the strongly typed nature of C++), you cannot do that. I would use just one function signature and then adapt all of my functions to comply with it. Within this approach you might possibly find useful std::function[^].

STL

delegates

C++ universal-signature delegates

4 Feb 2019 by Richard MacCutchan

There is no easy way around this, since the compiler needs to check the call matches the function signature. You could define each function to take a void* as its only parameter and then cast it internally to the correct structure. Or you could use the varargs option where you pass one fixed...

STL

delegates

The Amazing Performance of C++17 Parallel Algorithms, is it Possible?

25 Nov 2018 by Bartlomiej Filipek

What performance can we get from C++17 parallel algorithms?

Reference and pointer typecasting in C++

26 Sep 2018 by steffi123

I am able to typecast reference of vector to reference of vector whereas I am unable to typecast vector to vector. I am getting the error C2440: 'reinterpret_cast' : cannot convert from 'std::vector' to 'std::vector' why? And I am able to typecast void* to...

C++

STL

Reference and pointer typecasting in C++

26 Sep 2018 by Rick York

One thing I find helpful in these situations is to use type definitions. Here are a couple types I would define in this situation :typedef struct Foo * pFoo; typedef std::vector vecpfoo; Then I would adjust your functions to this :void reportFoo( int index, pFoo pf ) { cin

C++

STL

Reference and pointer typecasting in C++

25 Sep 2018 by KarstenK

Type casting can lead to strange errors when done wrong, so it is better to avoid this or handle it with greatest care. So avoid type casting to void* because the programmer and the compiler are loosing precious informations about the objects. Any up cast is leading to different handling of...

C++

STL

Reference and pointer typecasting in C++

25 Sep 2018 by CPallini

The reason is simple: reinterpret_cast only works with pointers (this is the short answer, for the detailed one, feel free to read the documentation: reinterpret_cast conversion - cppreference.com[^]).

C++

STL

How to pass std::vector<void*> * as std::vector<mystruct*>* to a function

24 Sep 2018 by steffi123

Hi, How to pass std::vector * as std::vector* to a function? The function declaration is void SetDataReferences(std::vector* pVector); if I pass std::vector * as std::vector* I am getting below error error C2664: 'SetDataReferences' : cannot...

C++

STL

How to pass std::vector<void*> * as std::vector<mystruct*>* to a function

24 Sep 2018 by KarstenK

The alternative is very clear: creating and passing the parameter in the right type. You should take this warning very serious because it screams for a coding flaw. //TODO: Change the creation code of input parameter

C++

STL

How to pass std::vector<void*> * as std::vector<mystruct*>* to a function

24 Sep 2018 by CPallini

Provided you are sure the vector you are passing actually contains pointer to valid MyStruct instances, a reinterpret_cast[^] would do the trick. Try, for instance: #include #include using namespace std; struct Foo { string s; int i; }; void reportFooVector( vector...

C++

STL

CppEvent - How to Implement Events using Standard C++

13 Aug 2018 by Shmuel Zang

This article shows how we can implement a thread-safe events (similar to .NET events) mechanism using the standard C++ library.

Combinations in C++

5 Jun 2018 by Shao Voon Wong

An article on finding combinations

Memory Dump to outstream

4 Apr 2018 by Orjan Westin

Function and supporting class to write a memory dump with hex values and characters to an output stream

C++

STL

How to search in vector of structure by a structure attribute?

26 Mar 2018 by Vishal Bhatia0112

I have a Vector of structure that is sorted on based of a variable. For ex: struct Client { string name; int sm_index; int client_id; int user_id; } Sorted on based of sm_index. How can i find and fetch the data of that struture whose sm_index matches our target structure. ...

How to search in vector of structure by a structure attribute?

26 Mar 2018 by Rick York

Here's an example of how to use binary_search : bool Compare( const Client& lhs, const Client& rhs ) { return ( lhs.client_id clientVec ) { return binary_search( clientVec.begin(), clientVec.end(),...

How to search in vector of structure by a structure attribute?

25 Mar 2018 by KarstenK

Thats sounds poor, because iteration is one main standout feature of the vector container class. If your vector is sorted I would suggest the faster binary search but I think that you may consider this in a later stage of your project.

How to search in vector of structure by a structure attribute?

25 Mar 2018 by Richard MacCutchan

See functions[^]

C++ matrix expression template

20 Mar 2018 by Rick York

The right and left parameters would be of type LeftOp and RightOp and those are of type Matrix. You can see this by looking at the template code in the listing. Here are two snippets : template class EtMatrixAdd { public: ...

C++14

STL

templates

C++ matrix expression template

20 Mar 2018 by Member 13737179

Hi, I am new to expression template programming, I went through this tutorial. It's pretty good I understand things a bit but not able to replicate code to working one. Can someone help ? What I did -> From [listing 3] I saved it as matrix.h file but don't know how can I make a new matrix...

C++14

STL

templates

Error on save and load data on queue and stack data structures using boost library

29 Jan 2018 by saide_a

yesterday I found out something first when I use cout for printing my structure it works Okey. but when I want to read and write from file this happens, this problem occurs only with use of stack and queue. At second, I used headers for serialization in main function before, but when I use that...

C++

Boost

STL

Error on save and load data on queue and stack data structures using boost library

27 Jan 2018 by saide_a

I am new in using boost serialization library. I want to save and load data to and from STL structures using text_iarchive and text_oarchive. I used bellow code for that: mystruct test; test.initial(); { std::ofstream ofs("filename.dat"); boost::archive::text_oarchive ar(ofs); ar &...

C++

Boost

STL

HPC Template Library, A Supplement to the STL

15 Dec 2017 by trident99

The HPC Template Library is a supplement to the Standard Template Library providing threadsafe containers.

STL std::string not work in C++ builder XE10.2

7 Dec 2017 by draculamx

std::string f; f.append(0,2); f[0]=2; f[1]=1; //f="cd"; std::string s; s.append(0,5); s[0]=1; s[1]=2; s[2]=1; s[3]=3; s[4]=1; //s="abcde"; unsigned int pp=0; pp=s.find(f); this code work fine in Visual Studio 2008 sp1,operation system is Win7 64Bit sp1 but in C++ Builder...

STL std::string not work in C++ builder XE10.2

7 Dec 2017 by draculamx

s.append(0,5) //wrong s.append(5,0) //right sorry for waste your time......

STL std::string not work in C++ builder XE10.2

6 Dec 2017 by draculamx

OK，someone told me a solution change "f.append(0,2); s.append(0,5)" to "f.resize(2); s.resize(5)" then it's work fine!!

STL std::string not work in C++ builder XE10.2

6 Dec 2017 by draculamx

the std:string not only use for charactors,in fact it can store data like BYTE each element. so ,why "abcde" work,but "0x1,0x2,0x3" not work ?? and these code work in Visual Studio 2008 fine.....

STL std::string not work in C++ builder XE10.2

6 Dec 2017 by Rick York

I think you could write : f[0] = 'c'; f[1] = 'd'; or f[0] = 'a' + 2; f[1] = 'a' + 3;

Day 41 of 100 Days of VR: Creating a VR First Person Shooter IV – Game Over Panels

21 Nov 2017 by IAmJoshChang

How to create a VR first person shooter IV - Game over panels

STL

Day 31 of 100 Days of VR: Stopping The Time Score System When The Game Is Over

22 Oct 2017 by IAmJoshChang

How to stop the time score system when the game is over

STL

How Do I Write A Code To Implement Quine Mccluskey's Method For Minimisation

10 Oct 2017 by Member 11033237

please help me coding (in language C)quine mcCluskey's method for solving upto 8,9 or 10 variables whose minterms are to be generated automatically, only the no. of minterms, no.of variables and vectors of minterms are user given

STL

How to Run Your Libgdx Game on Your Desktop

25 Sep 2017 by IAmJoshChang

How to run your Libgdx game on your desktop

STL

Month-Name Ordering

18 Sep 2017 by David Wincelberg

Sort by month name in database tables, filenames or strings

The Concave Hull of a Set of Points

16 Aug 2017 by Alasdair Craig

A C++ implementation of a published algorithm for computing the concave hull using a k-nearest neighbour approach.

How to locate the crashed code position using VS 2010 debug?

24 Jul 2017 by Mark Danniel

I wrote a MFC application program in VS2010 IDE.I used some STL containers such as vector,map ,etc.But after ruuning my program,the program crashed.The error message said "map/set iterator not dereferencable!".So what shoud I do can find where the code caused the crash?How to locate the...

STL

MFC

How to locate the crashed code position using VS 2010 debug?

24 Jul 2017 by OriginalGriff

Use the debugger. Run your app in the debugger - it's pretty simple, google will find you instructions - and when it crashes, use the stack trace to locate the function in your code that made it crash. Put a breakpoint at the top of the function, and your your app again. This time, it will stop...

STL

MFC