Add functions to convert from Span<const uint8> and std::string_view

These can replace the current der::Input-specific string_view methods. I
converted many of the uses within the library, but we should take a pass
over the library and turn many of the std::strings into
std::vector<uint8_t>.

On MSVC, we have to pass /Zc:__cplusplus for __cplusplus to be set
correctly. For now, I'm going to try just adding the flag, but if pki
gets used in more places before we bump our minimum to C++17, we may
want to start looking at _MSVC_LANG instead.

There are actually a few places outside of pki that could use this, but
we sadly can't use them until we require C++17 across the board.

Bug: 661
Change-Id: I1002d9f2e1e4a2592760e8938560894d42a9b58c
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/65908
Reviewed-by: Bob Beck <bbe@google.com>
Reviewed-by: Matt Mueller <mattm@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/pki/input.h b/pki/input.h
index 4a94110..30ce5d4 100644
--- a/pki/input.h
+++ b/pki/input.h
@@ -44,6 +44,8 @@ class OPENSSL_EXPORT Input {
   constexpr explicit Input(const uint8_t *data, size_t len)
       : data_(MakeConstSpan(data, len)) {}
 
+  // Deprecated: Use StringAsBytes.
+  //
   // Creates an Input from a std::string_view. The constructed Input is only
   // valid as long as |data| points to live memory. If constructed from, say, a
   // |std::string|, mutating the vector will invalidate the Input.
@@ -69,13 +71,17 @@ class OPENSSL_EXPORT Input {
   constexpr Input first(size_t len) const { return Input(data_.first(len)); }
   constexpr Input last(size_t len) const { return Input(data_.last(len)); }
 
+  // Deprecated: use BytesAsStringView and convert to std::string.
+  //
   // Returns a copy of the data represented by this object as a std::string.
   std::string AsString() const;
 
+  // Deprecated: Use ByteAsString. 
+  //
   // Returns a std::string_view pointing to the same data as the Input. The
   // resulting string_view must not outlive the data that was used to construct
   // this Input.
-  std::string_view AsStringView() const;
+  std::string_view AsStringView() const { return BytesAsStringView(data_); }
 
   // Deprecated: This class implicitly converts to bssl::Span<const uint8_t>.
   //