Use function templates to deduce class template argument types (where feasible)

Writing the template argument types explicitly can be tedious and unnecessarily verbose.

tuple<int, string, double> t1 = {1, "Hamlet", 3.14};   // explicit type
auto t2 = make_tuple(1, "Ophelia"s, 3.14);         // better; deduced type

Note the use of the s suffix to ensure that the string is a std::string, rather than a C-style string.

Since you can trivially write a make_T function, so could the compiler. Thus, make_T functions might become redundant in the future.

Sometimes there isn't a good way of getting the template arguments deduced and sometimes, you want to specify the arguments explicitly:

vector<double> v = { 1, 2, 3, 7.9, 15.99 };
list<Record*> lst;

Note that C++17 will make this rule redundant by allowing the template arguments to be deduced directly from constructor arguments: Template parameter deduction for constructors (Rev. 3). For example:

tuple t1 = {1, "Hamlet"s, 3.14}; // deduced: tuple<int, string, double>

Flag uses where an explicitly specialized type exactly matches the types of the arguments used.

Templates and generic programming

T.44

Writing the template argument types explicitly can be tedious and unnecessarily verbose.

tuple<int, string, double> t1 = {1, "Hamlet", 3.14};   // explicit type
auto t2 = make_tuple(1, "Ophelia"s, 3.14);         // better; deduced type

Note the use of the s suffix to ensure that the string is a std::string, rather than a C-style string.

Since you can trivially write a make_T function, so could the compiler. Thus, make_T functions might become redundant in the future.

Sometimes there isn't a good way of getting the template arguments deduced and sometimes, you want to specify the arguments explicitly:

vector<double> v = { 1, 2, 3, 7.9, 15.99 };
list<Record*> lst;

tuple t1 = {1, "Hamlet"s, 3.14}; // deduced: tuple<int, string, double>

Flag uses where an explicitly specialized type exactly matches the types of the arguments used.