message: Allow conversion from const char* to string_view
diff: #pragma once
  #include <cstddef>
  +#include <cstring>
  #include <iosfwd>
  #include <iterator>
  #include <limits>
  @@ -105,11 +106,10 @@ public:
  // nop
  }
  - template <size_t N>
  - constexpr string_view(const char (&cstr)[N]) noexcept
  + constexpr string_view(const char* cstr) noexcept
  : data_(cstr),
  - size_(N - 1) {
  - static_assert(N > 0, "");
  + size_(strlen(cstr)) {
  + // nop
  }
  constexpr string_view(const string_view&) noexcept = default;
  