Can I add a deduction guide to `std` namespace?

c++, c++-faq, deduction-guide, language-lawyer, template-argument-deduction

Solution

[namespace.std]/2.4:

The behavior of a C++ program is undefined if it declares [...] a deduction guide for any standard library class template.

Problem

Suppose I want to make a new deduction guide making the following possible ? ``` std::string str; std::basic_string_view sv = str; ``` Would that be an Ok customization ?

Original source