FUDI: use std::from_chars()

Author: mgeier

src/fudi/connection.h

@@ -70,8 +70,7 @@ class Connection : public std::enable_shared_from_this<Connection>
   void _read_socket()
   {
     auto self{shared_from_this()};
-    // NB: minus one for zero termination
-    auto buffersize = _read_buffer.size() - 1;
+    auto buffersize = _read_buffer.size();
     if (_read_offset >= buffersize)
     {
       SSR_ERROR("Input buffer is full; dropping contents");
@@ -85,9 +84,6 @@ class Connection : public std::enable_shared_from_this<Connection>
           if (!ec)
           {
             _read_offset += length;
-            // NB: zero termination is needed for std::strtof and std::strtoul
-            // TODO: remove this once std::from_chars is used instead.
-            _read_buffer[_read_offset] = '\0';
             auto input = std::string_view{_read_buffer.data(), _read_offset};
             _parser.parse(input);
             auto consumed = input.data() - _read_buffer.data();
@@ -104,8 +100,7 @@ class Connection : public std::enable_shared_from_this<Connection>
   }
 
   // See MAXPDSTRING in m_pd.h, and INBUFSIZE in s_inter.c
-  // ... plus one for zero termination
-  std::array<char, 4096 + 1> _read_buffer;
+  std::array<char, 4096> _read_buffer;
   std::size_t _read_offset{0};
   asio::ip::tcp::socket _socket;
   Subscriber _subscriber;

src/fudi/parser.h

@@ -28,7 +28,7 @@
 #ifndef SSR_FUDI_PARSER_H
 #define SSR_FUDI_PARSER_H
 
-#include <cstdlib>  // for std::strtof(), std::strtoul()
+#include <charconv>  // for std::from_chars
 #include <functional>  // for std::function
 #include <variant>
 
@@ -280,9 +280,10 @@ constexpr auto parse_string(std::string& value)
 constexpr auto id_or_number(std::variant<std::string, unsigned int>& value)
 {
   return [&value](std::string_view& input) {
-    char* str_end;
-    unsigned int number = std::strtoul(input.data(), &str_end, 10);
-    if (str_end == input.data())
+    unsigned int number{};
+    auto [str_end, ec] = std::from_chars(
+        input.data(), input.data() + input.size(), number);
+    if (ec != std::errc())
     {
       std::string temp;
       auto result = parse_string(temp)(input);
@@ -333,10 +334,9 @@ constexpr auto parse_float(float& value)
     {
       return Match::incomplete;
     }
-    char* str_end;
-    // TODO: use std::from_chars once it is widely available
-    value = std::strtof(temp.data(), &str_end);
-    if (str_end == temp.data())
+    auto [str_end, ec] = std::from_chars(
+        temp.data(), temp.data() + temp.size(), value);
+    if (ec != std::errc())
     {
       return Match::no;
     }