A C++ library which enables the construction of containers maintaining one or more indices with different sorting and access semantics.
Questions tagged [boost-multi-index]
248 questions
1
vote
1 answer
How to using boost::multi_index with struct in struct?
I have a vector containing information called ST_ThepInfo.
My problem is when using struct ST_ThepInfo in struct Infovalue_t.
struct ST_ThepInfo
{
int length;
string ex;
int weight;
};
struct Infovalue_t {
ST_ThepInfo s;
int…
Yen Dang
- 268
- 2
- 9
1
vote
3 answers
Can't compile boost::multi_index_container
What is wrong in the code below?
#if !defined(NDEBUG)
#define BOOST_MULTI_INDEX_ENABLE_INVARIANT_CHECKING
#define BOOST_MULTI_INDEX_ENABLE_SAFE_MODE
#endif
#include
#include…
Alexey Starinsky
- 3,699
- 3
- 21
- 57
1
vote
1 answer
MultiIndex containers -- offering vector and set access
I have an application where, first, an std::vector object is generated. Then, some operations need to be performed on this object viewed as an std::set where the order does not matter and repetitions don't count.
At present, I explicitly…
Tryer
- 3,580
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- 49
1
vote
1 answer
Reversing a graph while maintaining access to edges sorted by source or target vertex
Note: I changed the title of the question because it turns out the following text and minimal example reflect my original problem poorly. The original title was "Interchanging two similar indices in a boost multi-index container"
I'm implementing…
Isaac Ren
- 113
- 5
1
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2 answers
Boost Multi-Index remove elements using list of indexes
My multiindex looks like this:
using pair = std::pair;
struct Hasher{
std::size_t operator()(const int& k) const{
return std::hash()(k);
}
};
using memberFirst = member<
pair,
…
Apsik
- 53
- 6
1
vote
3 answers
Is it possible to have boost multi_index container index one element with 2 key values?
I want to have my boost multi_index container index one element with multiple key values on the same index. Is that possible?
struct Student {
int Id;
std::unordred_set Clubs;
};
Suppose this student belongs to Technology and…
Ben
- 33
- 4
1
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2 answers
Boost.Multiindex composite_key key storage
Let's say I form a composite_key of three integer members for a boost::multi_index_container. The keys will span every combination of three integers within some range ({0, 0, 0}, {0, 0, 1}, {0, 0, 2}, etc). Internally, does boost store each of these…
Sean
- 380
- 1
- 11
1
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3 answers
Multiple indexing with big data set of small data: space inefficient?
I am not at all an expert in database design, so I will put my need in plain words before I try to translate it in CS terms: I am trying to find the right way to iterate quickly over large subsets (say ~100Mo of double) of data, in a potentially…
Sam
- 117
- 11
1
vote
1 answer
Find element in boost multi_index_container
In my code I need to have a functionality to iterate over all elements and check if there some element already exists possibly as soon as possible, so my choice fell on boost multi index container where I can use vector and unordered_set interface…
bladzio
- 414
- 3
- 15
1
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2 answers
Can I use lambda as a hashing function in boost::multi_index hash-like interface?
Is it possible to use lambda for hashing in hashed__unique interface for boost::multi_index?
See this example: https://godbolt.org/z/1voof3
I also saw this: How to use lambda function as hash function in unordered_map? where the answer…
Daniel
- 980
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1
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2 answers
How to find most commonly occurring non-unique keys in Boost MultiIndex?
Boost MultiIndex Container, when defined to have hashed_non_unique keys, can group equivalent keys together and return them all against an equal_range query, as mentioned here. But I see no way of querying the largest range (or n largest ranges) in…
Subhamoy S.
- 6,566
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1
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1 answer
Cannot compile: error: expected primary-expression before '(' token
I cannot get this compile:
// main.cpp
#include
#include
#include
#include
#include…
Agrim Pathak
- 3,047
- 4
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- 43
1
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1 answer
Storing references/pointers to Boost MultiSet indexes
I'm trying to build two classes Collection and CollectionView, which is an abstraction on top of Boost.MultiIndex. The idea is somewhat simple: Give an instance of type Collection to a CollectionView, and it'll handle rendering. The Collection adds…
Emil Ahlbäck
- 6,085
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- 39
- 54
1
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1 answer
modify() boost multi-index keys during iteration
Let's assume i have following data struct with 2 int values key_x and key_y + some additional fields.
struct data_object {
int key_x;
int key_y;
//....
};
And boost multi_index_container with composite_key, including key_x and key_y…
johnbrovi
- 82
- 1
- 8
1
vote
1 answer
so many error when i add certain .cpp file
i made small program which does some functions and i tested it and it worked as i wish.
Then i add its .h and .cpp files to another program to use it but when i add the .cpp file it gives me 100s of errors related to boostmultiindex which i use in…
ahmed allam
- 377
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- 15