A std::pair is an ordered, heterogeneous sequence of exactly two objects (it is a special case of std::tuple).
std::pair is a part of the C++ Standard Library, defined in the header <utility>.
Questions tagged [std-pair]
776 questions
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1 answer
Dereference the first part of the pair object for an unordered map
I have a C++ 03 compliant compiler. I am using a pair object when inserting the element into an unordered map using the following code:
unordered_map mymap;
pair::iterator,bool> ret;
ret =…
user1593881
0
votes
1 answer
Extending std::vector> with own functionality
My C++11 is too weak to find a solution. I have lot of std::vector> variables in my project and therefore the code to check if an entry does exist repeats:
std::vector>…
Peter VARGA
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Using arrays in std::pair to extend the amount of data
I'm trying to extend someone else's code which is using std::queue and std::pair types pretty frequently. For the following code, I need to extend the number of variables in std::pair.second and prefer it to be more flexible for number of variables…
Abdullah Giray Yağlıkçı
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2 answers
c++ Sorting a vector based on values of other vector, or what's faster?
There are a couple of other posts about sorting a vector A based on values in another vector B. Most of the other answers tell to create a struct or a class to combine the values into one object and use std::sort.
Though I'm curious about the…
pollux
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A vector of pairs: first pair values are non-sorted and second pair values are sorted: how to find a sorted value when having the non-sorted one
I have a vector of pairs, as shown below. First pair values are non-sorted and second pair values are sorted (starting from zero). I might want to store data by implementing std::vector and std::pair. When I have a first pair value (non-sorted),…
Megidd
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1 answer
C++ Using a lambda in find_if to find pair variables
So I'm having trouble understanding lambdas and how they work, specifically if i have a
std::vector> storage;
and want to write a function that looks like
bool VNS::remove(const std::string& host) {
auto end =…
enrm
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C++ adding std::pair to template base class
I have a weird behavior in C++ code. I have an abstract base class Symbolic:
template
class Symbolic
{
protected:
vector > monomials;
public:
virtual ~Symbolic() {}
virtual ostream &print(ostream &o) const…
JusticeJuice
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- 7
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Can not Create pair - constructor
I can not create a pair when one of the classes in the pair in a class Edge
I know it is because of the constructors in Edge, but I do not know what is wrong.
The Edge constructor has a Token because I wanted to make sure that only an Object of type…
Bojack
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Map, pair-vector or two vectors...?
I read through some posts and "wikis" but still cannot decide what approach is suitable for my problem.
I create a class called Sample which contains a certain number of compounds (lets say this is another class Nuclide) at a certain relative…
LCsa
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#include in dev c++ header file
i am trying to create a header file in c++ with the following code
#ifndef dictionary_h
#define dictionary_h
#include
using namespace std;
template
class dictionary
{
virtual bool empty() const=0;
virtual int…
Pradeep
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1 answer
Multiset of pair, find
I need to find and erase a value in mutliset of pair sorted by my own function. Apparently, .find always returns the iterator to the end, not to the searched value. Any tips? This is the function :
struct cmp
{
bool operator() (const para &a,…
Muco
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votes
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Read file (containing int, string) to vector of pairs using ifstream
I'm trying to read a text file into a vector of pairs. The text file contains the following:
The first line tells, how many strings there are. The second line is an int, telling how many characters there are in the (first) string. And then, the…
Elska
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3 answers
Confused of declaring this kind of array
I was reading this code
there is a line : pair approach[1 << 18][17]
I don't know what is the meaning of this declaration : approach[ 1<<18 ][17];
Can anyone help?
Kadaj13
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Run length encoding a vector
I have been reading on the forum many times before but today I cannot figure out why I am having an error in my code so if anyone can point out to why I am getting these errors I would be thankful. I am new to template and do not understand why…
Rooth
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Compiler error when constructing a vector of pairs
Please can someone help explain why I get an error when compiling the following code using Xcode 5.1 on OS X. Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn).
I want construct X below, passing it a vector of pairs.
#include…
ksl
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