c++ - How to re-write templated function to handle type deduction -


so, have search function map container:

    template <typename key, typename t>     void searchinmapbykey(std::map<key,t> map, t keyvalue)     {         if(map.empty())         {             std::cout << "map empty, nothing search for..." << "\n";         }         else         {             for(const auto & element : map)             {                 if(element.first==keyvalue)                 {                     std::cout << keyvalue << "matches key value " << " in map" << "\n";                 }             }         }     }

and seem running deducing type issues, error:

candidate template ignored: deduced conflicting types parameter 't' ('std::__1::basic_string<char>' vs. 'int')

when try test following code:

        map<int,string> mymap;         mymap.emplace(1,string("a"));         mymap.emplace(2,string("b"));         mymap.emplace(3,string("c"));         searchinmapbykey(mymap,1);

because compiler doesn't know type associate "t", integer or string.

now, asked similar question same type of error , able solve issue using c++ style strings. however, don't want keep handling conflicting type deduction errors on case case basis, , wondering how write function (using templates) compiler better deduce type should associated "t" outset?

the problem mismatch between type of map , key types. fix not correcting order of parameters std::map argument, changing definition more generic.

template <typename maptype, typename keytype> void searchinmapbykey(const maptype & map, keytype key) {     if(map.empty()) {         std::cout << "map empty, nothing search for..." << "\n";         return;     }            for(const auto & element : map) {         if(element.first==keyvalue) {             std::cout << keyvalue << "matches key value " << " in map" << "\n";         }     } }

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