// retorn position [ 0, (N-1) ] if found
// return invalid position N if not found
template < typename SEQUENCE_CONTAINER >
typename SEQUENCE_CONTAINER::size_type lsearch( const SEQUENCE_CONTAINER& seq,
                            const typename SEQUENCE_CONTAINER::value_type& data )
{
   typename SEQUENCE_CONTAINER::size_type pos = 0 ;

	for( const auto& value : seq )
	{
		if( data == value ) return pos ;
		else ++pos ;
	}

	return seq.size() ;
}

#include <vector>
#include <list>
#include <string>
#include <iostream>

int main()
{
    std::vector<int> vec { 53, 65, 64, 74, 74, 74, 32, 17, 23, 29, 86 } ;
    auto f = lsearch( vec, 17 ) ;
    if( f != vec.size() ) std::cout << "found at position " << f << '\n' ;

    std::list<std::string> lst { "abc", "def", "ghi", "jkl", "mnop", "qrst", "uvwxyz" } ;
    std::cout << lsearch( lst, "mnop" ) << '\n' ;

    std::string phrase = "STL container template for this function" ;
    std::cout << lsearch( phrase, 'L' ) << '\n' ;
}