Here is some valid syntax:
std::uniform_real_distribution<> randomizer(0, 100);
How does it work, does it automatically deduce the object template? Why is it necessary to write <> at the end of the type? Can I not remove the <> and it will be the same?
Typically this can be used and works when the first and succeeding, or only, parameter has a default template argument (type or value if it is an integral). An additional case is when there is a template argument pack and it is empty.
The <> is still needed to identify it as a template type.
In this case the type is declared as;
template <class RealType = double>
class uniform_real_distribution;
Hence the default RealType for the template class uniform_real_distribution is double. It amounts to std::uniform_real_distribution<double>.
With reference to the C++ WD n4527, §14.3/4 (Template arguments)
When template argument packs or default template-arguments are used, a template-argument list can be empty. In that case the empty
<>brackets shall still be used as the template-argument-list. [ Example:template<class T = char> class String; String<>* p; // OK: String<char> String* q; // syntax error template<class ... Elements> class Tuple; Tuple<>* t; // OK: Elements is empty Tuple* u; // syntax error- end example ]