Update README.md

Rearranged and updated the table.
Added a second table of concepts that exist in the Microsoft GSL that do not exist in the C++ Core Guidelines

1 files changed, 29 insertions, 27 deletions

diff --git a/README.md b/README.md
index 2e3c055..54b3fb5 100644
--- a/README.md
+++ b/README.md
@@ -20,52 +20,48 @@ This project has adopted the [Microsoft Open Source Code of Conduct](https://ope
 This project makes use of the [Google Test](https://github.com/google/googletest) testing library. Please see the [ThirdPartyNotices.txt](./ThirdPartyNotices.txt) file for details regarding the licensing of Google Test.
 
 # Supported features
-GSL implements the following utilities:
+## Microsoft GSL implements the following from the C++ Core Guidelines:
 
 Feature                            | Supported? | Description
 -----------------------------------|:----------:|-------------
 [**1. Views**][cg-views]           |            |
-owner                              | ☑   | an alias for a raw pointer for its better expressiveness
+owner                              | ☑   | an alias for a raw pointer
 not_null                           | ☑   | restricts a pointer / smart pointer to hold non-null values
 strict_not_null                    | ☑   | a stricter version of `not_null` with explicit constructors
-span                               | ☑   | spans a range starting from a pointer to pointer + size
+span                               | ☑   | a view over a contiguous sequence of memory. Based on the standardized verison of `std::span`, however `gsl::span` enforces bounds checking.
 span_p                             | ☐   | spans a range starting from a pointer to the first place for which the predicate is true
-multi_span                         | ☑   | spans a contiguous region of memory, which represents a multidimensional array
-strided_span                       | ☑   | **I HAVE NO IDEA WHAT IT DOES, ANYONE???!!!**
 basic_zstring                      | ☑   | a pointer to a C-string (zero-terminated array) with a templated char type
-zstring                            | ☑   | an alias to `basic_zstring` where the char type is char
-wzstring                           | ☑   | an alias to `basic_zstring` where the char type is wchar_t
-czstring                           | ☑   | like `zstring` but the char type is also const
-cwzstring                          | ☑   | like `wzstring` but the char type is also const
-u16zstring                         | ☑   | an alias to `basic_zstring` where the char type is char16_t
-cu16zstring                        | ☑   | like `u16zstring` but the char type is also const
-u32zstring                         | ☑   | an alias to `basic_zstring` where the char type is char32_t
-cu32zstring                        | ☑   | like `u32zstring` but the char type is also const
-basic_string_span                  | ☑   | like `span` but for strings with a templated string type
-string_span                        | ☑   | an alias to `basic_string_span` where the char type is char
-cstring_span                       | ☑   | like `string_span` but the char type is also const
-wstring_span                       | ☑   | an alias to `basic_string_span` where the char type is wchar_t
-cwstring_span                      | ☑   | like `wstring_span` but the char type is also const
-u16string_span                     | ☑   | an alias to `basic_string_span` where the char type is char16_t
-cu16string_span                    | ☑   | like `u16string_span` but the char type is also const
-u32string_span                     | ☑   | an alias to `basic_string_span` where the char type is char32_t
-cu32string_span                    | ☑   | like `u32string_span` but the char type is also const
+zstring                            | ☑   | an alias to `basic_zstring` with a char type of char
+czstring                           | ☑   | an alias to `basic_zstring` with a char type of const char
+wzstring                           | ☑   | an alias to `basic_zstring` with a char type of wchar_t
+cwzstring                          | ☑   | an alias to `basic_zstring` with a char type of const wchar_t
+u16zstring                         | ☑   | an alias to `basic_zstring` with a char type of char16_t
+cu16zstring                        | ☑   | an alias to `basic_zstring` with a char type of const char16_t
+u32zstring                         | ☑   | an alias to `basic_zstring` with a char type of char32_t
+cu32zstring                        | ☑   | an alias to `basic_zstring` with a char type of const char32_t
+basic_string_span                  | ☑   | like `span` but for strings with a templated char type
+string_span                        | ☑   | an alias to `basic_string_span` with a char type of char
+cstring_span                       | ☑   | an alias to `basic_string_span` with a char type of const char
+wstring_span                       | ☑   | an alias to `basic_string_span` with a char type of wchar_t
+cwstring_span                      | ☑   | an alias to `basic_string_span` with a char type of const wchar_t
+u16string_span                     | ☑   | an alias to `basic_string_span` with a char type of char16_t
+cu16string_span                    | ☑   | an alias to `basic_string_span` with a char type of const char16_t
+u32string_span                     | ☑   | an alias to `basic_string_span` with a char type of char32_t
+cu32string_span                    | ☑   | an alias to `basic_string_span` with a char type of const char32_t
 [**2. Owners**][cg-owners]         |            |
 unique_ptr                         | ☑   | an alias to `std::unique_ptr`
 shared_ptr                         | ☑   | an alias to `std::shared_ptr`
 stack_array                        | ☐   | a stack-allocated array
 dyn_array                          | ☐   | a heap-allocated array
 [**3. Assertions**][cg-assertions] |            |
-Expects                            | ☑   | a precondition assertion; on failure it either terminates or throws `fail_fast`
-Ensures                            | ☑   | a postcondition assertion; on failure it either terminates or throws `fail_fast`
+Expects                            | ☑   | a precondition assertion; on failure it terminates
+Ensures                            | ☑   | a postcondition assertion; on failure it terminates
 [**4. Utitilies**][cg-utilities]   |            |
 move_owner                         | ☐   | a helper function that moves one `owner` to the other
-release_owner                      | ☐   | a helper function that releases ownership of the passed `owner` and returns a new `owner`
 byte                               | ☑   | either an alias to std::byte or a byte type
-fail_fast                          | ☑   | a custom exception type thrown by assertions
 final_action                       | ☑   | a RAII style class that invokes a functor on its destruction
 finally                            | ☑   | a helper function instantiating `final_action`
-GSL_SUPPRESS                       | ☑   | a macro that takes an argument and tries to turn it into `[[gsl::suppress(x)]]`
+GSL_SUPPRESS                       | ☑   | a macro that takes an argument and turns it into `[[gsl::suppress(x)]]` or `[[gsl::suppress("x")]]`
 [[implicit]]                       | ☐   | a "marker" to put on single-argument constructors to explicitly make them non-explicit
 index                              | ☑   | a type to use for all container and array indexing (currently an alias for std::ptrdiff_t)
 joining_thread                     | ☐   | a RAII style version of `std::thread` that joins
@@ -74,6 +70,12 @@ narrow_cast                        | ☑   | a narrowing cast for values an
 narrowing_error                    | ☑   | a custom exception type thrown by `narrow()`
 [**5. Concepts**][cg-concepts]     | ☐   |
 
+## The following features do not exist in C++ Core Guidelines:
+Feature                            | Supported? | Description
+-----------------------------------|:----------:|-------------
+multi_span                         | ☐   | Deprecated. Support for this type has been discontinued.
+strided_span                       | ☐   | Deprecated. Support for this type has been discontinued.
+
 This is based on [CppCoreGuidelines semi-specification](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#gsl-guidelines-support-library).
 
 [cg-views]: https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#gslview-views