Small reading utility.

2019/src/day03.cpp

@@ -27,7 +27,7 @@ namespace {
         for (auto entry = aoc2019::strtok(line); !line.empty() || !entry.empty(); entry = aoc2019::strtok(line)) {
             const auto dir = DIRECTION_MAP.at(entry[0]);
             std::size_t amount = 0;
-            std::from_chars(entry.data() + 1, entry.data() + entry.size(), amount);
+            aoc2019::from_chars(entry.substr(1), amount);
             assert(amount > 0 && "Must have some valid direction");
 
             for (std::size_t i = 0; i < amount; ++i) {

2019/src/utils.hpp

@@ -1,10 +1,16 @@
 #pragma once
 
+#include <charconv>
 #include <functional>
 #include <string_view>
 
 namespace aoc2019 {
 
+    template<typename T>
+    inline std::from_chars_result from_chars(std::string_view str, T& value) {
+        return std::from_chars(str.data(), str.data() + str.size(), value);
+    }
+
     template<typename T>
     void combine_hash(std::size_t& seed, const T& o) {
         // Algorithm taken from boost::combine_hash.