Hi all, I'm making a neural network and wanted to use a hash_map to keep weight references for output neurons for each neuron: class Neuron; //forward declaration was there (sorry I forgot to show it earlier) typedef double WEIGHT; typedef stdext::hash_map<boost::shared_ptr<Neuron>,WEIGHT> NeuronWeightMap; class Neuron { private: N...
Using the STL C++ hash_map... class MyKeyObject { std::string str1; std::string str2; bool operator==(...) { this.str1 == that.str1 ... } }; class MyData { std::string data1; int data2; std::string etcetc; }; like this... MyKeyObject a = MyKeyObject(...); MyData b = MyData(...); stdext::hash_map <MyKeyObjec...
vs2005 support ::stdext::hash_map ::std::map. however it seems ::stdext::hash_map's insert and remove OP is slower then ::std::map in my test. ( less then 10000 items) Interesting.... Can anyone offored a comparision article about them? ...
I was using std::hash_map<char*,T> and somehow managed to make it work but have now discovered that the default compare function, euqal_to<char*> does a pointer compare rather than a string compare. I've fixed this by making my own compare type (using C's strcmp and it's about 5 LOC) but I'd be slightly shocked if there wasn't one alread...
Hi, I am porting a program to AIX which takes use of hash_map in many places. For linux and solaris hash_map is included in _gnu_cxx package and stlport. However, I can't find hash_map on AIX platform. Anybody know? Btw, I have to use IBM compiler /usr/vacpp/bin/xlC. Thanks. ...
I am not to Clojure and attempting to figure out how to do this. I want to create a new hash-map that for a subset of the keys in the hash-map applies a function to the elements. What is the best way to do this? (let [my-map {:hello "World" :try "This" :foo "bar"}] (println (doToMap my-map [:hello :foo] (fn [k] (.toUpperCase k))...
This is my first time making a hash table. I'm trying to associate strings (the keys) with pointers to objects (the data) of class Strain. // Simulation.h #include <ext/hash_map> using namespace __gnu_cxx; struct eqstr { bool operator()(const char * s1, const char * s2) const { return strcmp(s1, s2) == 0; } }; ... hash_map< co...
This question is an offgrowth of my previous question on creating a hash table to store string keys and pointers as data. I'm getting a seg fault post-construction when I try to add entries to my hash table. I'm still very confused about what syntax is appropriate. I currently have (thanks to previous posters): // Simulation.h #include...
Hello, In some C++ program I have two classes - Abc and Xyz. The Abc class contains an integer member Foo, like in the following listing: class Abc { public: int Foo; Abc(int f) { Foo = f; } }; class Xyz{}; I'm using a map<Abc, Xyz> but the performance is extremly poor. That's why I'd like to use a hash_map<Abc, Xyz> (Dev-Cp...
Here's what I have, I am new to C++ so I am not sure if this is right... typedef pair<string, int>:: make_pair; hash_map <string, int> dict; dict.insert(make_pair("apple", 5)); I want to give my hash_map "apple", and I want to get back 5. How do I do it? ...
I've done something wrong in defining my class which is causing Microsoft's implementation of the hash_multimap to "miss." Here is my class: class TimeParameter { public: TimeParameter(int _year, int _julianDay, int _hour) : m_Year(_year), m_JulianDay(_julianDay), m_Hour(_hour){} int GetHour() const {re...
Hi, I have a question with hash_map and map in C++. I understand that map is in STL but hash_map is not a standard. What's the difference of them two? Any insights are strongly welcomed. Thanks! ...
Hi. I have a class like this: class Foo { long long Id; string x; string y; // other member variables and functions }; I would like to store this in a hash_set (or hash_map), but use the Id member variable as the key for inserting and searching. I'm not sure how I can do this. I thought of the following ways, but none of t...