Merge pull request #601 from cubbimew/issue583

update FAQ.55

Author: AndrewPardoe

CppCoreGuidelines.md

@@ -16095,9 +16095,9 @@ Because we want to use them immediately, and because they are temporary in that
 
 No. The GSL exists only to supply a few types and aliases that are not currently in the standard library. If the committee decides on standardized versions (of these or other types that fill the same need) then they can be removed from the GSL.
 
-### <a name="Faq-gsl-string-view"></a>FAQ.55: If you're using the standard types where available, why is the GSL `string_span` different from the `string_view` in the Library Fundamentals 1 Technical Specification? Why not just use the committee-approved `string_view`?
+### <a name="Faq-gsl-string-view"></a>FAQ.55: If you're using the standard types where available, why is the GSL `string_span` different from the `string_view` in the Library Fundamentals 1 Technical Specification and C++17 Working Paper? Why not just use the committee-approved `string_view`?
 
-Because `string_view` is still undergoing standardization, and is in a state for public review input to improve it. Types that appear in Technical Specifications (TSes) are not yet part of the International Standard (IS), and one reason they are put in TSes first is to gain experience with the feature before they are cast in a final form to become part of the standard. Some of the GSL authors are contributing what we have learned about `string_span` in the process of developing these guidelines, and a discussion of the differences between `string_view` and `string_span`, as a paper for the next ISO meeting for consideration along with all the other similar papers for the committee to consider as it decides on the final form of this feature.
+The consensus on the taxonomy of views for the C++ standard library was that "view" means "read-only", and "span" means "read/write". The read-only `string_view` was the first such component to complete the standardization process, while `span` and `string_span` are currently being considered for standardization.
 
 ### <a name="Faq-gsl-owner"></a>FAQ.56: Is `owner` the same as the proposed `observer_ptr`?