From 89bff1a8dcac2f951ac3f2c3d7415691ce16ca12 Mon Sep 17 00:00:00 2001
From: 0xFEEDC0DE64 <daniel@brunner.ninja>
Date: Thu, 15 Jul 2021 18:36:06 +0200
Subject: [PATCH] Added numberparsing

---
 CMakeLists.txt      |  1 +
 src/numberparsing.h | 75 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 src/numberparsing.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9e1087c..aff08d1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,6 +9,7 @@ set(headers
     src/cpptypesafeenum.h
     src/cpputils.h
     src/delayedconstruction.h
+    src/numberparsing.h
     src/refwhenneeded.h
     src/strutils.h
 )
diff --git a/src/numberparsing.h b/src/numberparsing.h
new file mode 100644
index 0000000..869bfb7
--- /dev/null
+++ b/src/numberparsing.h
@@ -0,0 +1,75 @@
+#pragma once
+
+// system includes
+#include <cstdint>
+#include <optional>
+#include <cstdio>
+#include <inttypes.h>
+
+namespace cpputils {
+template<typename T> constexpr std::optional<T> fromString(std::string_view str) = delete;
+
+template<> constexpr inline std::optional<int8_t> fromString<int8_t>(std::string_view str)
+{
+    int8_t val{};
+    if (std::sscanf(str.data(), "%" SCNi8, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+
+template<> constexpr inline std::optional<uint8_t> fromString<uint8_t>(std::string_view str)
+{
+    uint8_t val{};
+    if (std::sscanf(str.data(), "%" SCNu8, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+
+template<> constexpr inline std::optional<int16_t> fromString<int16_t>(std::string_view str)
+{
+    int16_t val{};
+    if (std::sscanf(str.data(), "%" SCNi16, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+
+template<> constexpr inline std::optional<uint16_t> fromString<uint16_t>(std::string_view str)
+{
+    uint16_t val{};
+    if (std::sscanf(str.data(), "%" SCNu16, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+
+template<> constexpr inline std::optional<int32_t> fromString<int32_t>(std::string_view str)
+{
+    int32_t val{};
+    if (std::sscanf(str.data(), "%" SCNi32, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+
+template<> constexpr inline std::optional<uint32_t> fromString<uint32_t>(std::string_view str)
+{
+    uint32_t val{};
+    if (std::sscanf(str.data(), "%" SCNu32, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+
+template<> constexpr inline std::optional<int64_t> fromString<int64_t>(std::string_view str)
+{
+    int64_t val{};
+    if (std::sscanf(str.data(), "%" SCNi64, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+
+template<> constexpr inline std::optional<uint64_t> fromString<uint64_t>(std::string_view str)
+{
+    uint64_t val{};
+    if (std::sscanf(str.data(), "%" SCNu64, &val) == 1)
+        return val;
+    return std::nullopt;
+}
+} // namespace cpputils