sysrap/tests/map_void_int.cc

0001 // name=map_void_int ; gcc $name.cc -std=c++11 -lstdc++ -o /tmp/$name && /tmp/$name
0002
0003 #include <cassert>
0004 #include <iostream>
0005 #include <vector>
0006
0007 #include <unordered_map>
0008 #include <cstring>
0009
0010 /**
0011 This tests a void* index cache for use with Geant4 objects that lack an index
0012 **/
0013
0014 struct Surf
0015 {
0016    const char* name ;
0017    int         index ;
0018    Surf(const char* name_, int index_) : name(strdup(name_)), index(index_) {}
0019 };
0020
0021 struct Turf
0022 {
0023    const char* name ;
0024    int         index ;
0025    Turf(const char* name_, int index_) : name(strdup(name_)), index(index_) {}
0026 };
0027
0028
0029 inline std::ostream& operator<<(std::ostream& os, const Surf& s){ os  << "Surf " << s.index << " " << s.name   ; return os; }
0030 inline std::ostream& operator<<(std::ostream& os, const Turf& s){ os  << "Turf " << s.index << " " << s.name   ; return os; }
0031
0032 struct Cache
0033 {
0034     typedef std::unordered_map<const void*, int>  MVI ;
0035     MVI  cache ;
0036
0037     void add(const void* obj, int index);
0038     int find(const void* obj) ;
0039 };
0040
0041 void Cache::add(const void* obj, int index)
0042 {
0043     cache[obj] = index  ;
0044 }
0045 int Cache::find(const void* obj)
0046 {
0047     MVI::const_iterator e = cache.end();
0048     MVI::const_iterator i = cache.find( obj );
0049     return i == e ? -1 : i->second ;
0050 }
0051
0052
0053 int main(int argc, char** argv)
0054 {
0055     Surf* r = new Surf("red",   100);
0056     Surf* g = new Surf("green", 200);
0057     Surf* b = new Surf("blue",  300);
0058
0059     Turf* c = new Turf("cyan",    1000);
0060     Turf* m = new Turf("magenta", 2000);
0061     Turf* y = new Turf("yellow",  3000);
0062     Turf* k = new Turf("black",   4000);
0063
0064     std::vector<const void*> oo = {r,g,b,c,m,y,k} ;
0065
0066     // hmm after mixing up the types need to have external info on which is which
0067     for(unsigned i=0 ; i < 3         ; i++) std::cout << *(Surf*)oo[i] << std::endl ;
0068     for(unsigned i=3 ; i < oo.size() ; i++) std::cout << *(Turf*)oo[i] << std::endl ;
0069
0070     Cache cache ;
0071
0072     for(unsigned i=0 ; i < oo.size() ; i++)
0073     {
0074         const void* o = oo[i] ;
0075
0076         cache.add(o, i);
0077         int idx = cache.find(o);
0078         assert( idx == int(i) );
0079     }
0080
0081     const void* anon = (const void*)m ;
0082     int idx_m = cache.find(anon) ;
0083     assert( idx_m == 4 );
0084
0085     return 0 ;
0086 }
0087
0088
0089
0090