Overhaul `RefPtr` and `String`

- `RefPtr` no longer tries to have distinct cases for interal-vs-external reference counts. Instead we always require an internal reference count.

  - Types the used `RefPtr` but weren't `RefObject` were made to inherit `RefObject`

  - The `ReferenceCounted` base class was removed, so that only `RefObject` remains

  - Implicit conversion from `RefPtr<T>` to `T*` added
    - This created some complicates for other types that relied on implicit conversions, so this isn't a net cleanup right now

- The main type that got messed up by the above was `String`, which previously held a `RefPtr<char, ...>`. This change thus *also* includes a major overhaul of `String`:

  - `String` now holds all its data via indirection, using a `StringRepresentation` that is a `RefObject`. This object holds a length, capacity, and directly stores the character data in its allocation. This means that `sizeof(String)==sizeof(void*)`

  - It is now possible to directly mutate a `String` by appending to its representation (we just need to ensure it has a reference count of `1`, possibly by cloning it). This means that `StringBuilder` is now basically just an idomatic use of `String`

  - A couple operations that just return sub-ranges of a `String` now return `StringSlice` to avoid allocation when it isn't needed. This required more work.

  - Indices into strings changed from `int` to `UInt` (which is pointer-sized). This had a bunch of follow-on changes because the value `-1` sometimes needs to be special-cased in code that uses indices. Further cleanups are probably needed here.

1 files changed, 3 insertions, 3 deletions

diff --git a/source/slang/options.cpp b/source/slang/options.cpp
index 62b45e025..cced0f0ff 100644
--- a/source/slang/options.cpp
+++ b/source/slang/options.cpp
@@ -238,7 +238,7 @@ struct OptionsParser
                     }
                     else
                     {
-                        fprintf(stderr, "unknown code generation target '%S'\n", name.ToWString());
+                        fprintf(stderr, "unknown code generation target '%S'\n", name.ToWString().begin());
                         exit(1);
                     }
 
@@ -302,7 +302,7 @@ struct OptionsParser
                     else if (name == "glslang") { passThrough = SLANG_PASS_THROUGH_GLSLANG; }
                     else
                     {
-                        fprintf(stderr, "unknown pass-through target '%S'\n", name.ToWString());
+                        fprintf(stderr, "unknown pass-through target '%S'\n", name.ToWString().begin());
                         exit(1);
                     }
 
@@ -387,7 +387,7 @@ struct OptionsParser
                 }
                 else
                 {
-                    fprintf(stderr, "unknown command-line option '%S'\n", argStr.ToWString());
+                    fprintf(stderr, "unknown command-line option '%S'\n", argStr.ToWString().begin());
                     // TODO: print a usage message
                     exit(1);
                 }