From 52f1f060557985a16c427a51a5de22a441b2a3cd Mon Sep 17 00:00:00 2001
From: csboo <csongiboo@gmail.com>
Date: Wed, 14 May 2025 03:01:50 +0200
Subject: [PATCH 1/6] feat(Parser): impl Parse for: int, std::string, bool

---
 include/Parser.hpp | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/include/Parser.hpp b/include/Parser.hpp
index 89eddfa..302e229 100644
--- a/include/Parser.hpp
+++ b/include/Parser.hpp
@@ -3,11 +3,42 @@
 #include "Arg.hpp"
 #include "utils.hpp"
 
+#include <cmath>
 #include <iostream>
 #include <optional>
 #include <string>
 #include <vector>
 
+template<typename T>
+struct Parse {
+    static_assert(sizeof(T) == 0, "No Parse<T> specialization defined for this type");
+};
+
+template<>
+struct Parse<int> {
+    static std::optional<int> parse(std::string_view s) {
+        int value;
+        auto [ptr, ec] = std::from_chars(s.data(), s.data() + s.size(), value);
+        if (ec == std::errc()) return value;
+        return std::nullopt;
+    }
+};
+
+template<>
+struct Parse<std::string> {
+    static std::optional<std::string> parse(std::string_view s) {
+        return std::string(s);
+    }
+};
+
+template<>
+struct Parse<bool> {
+    static std::optional<bool> parse(std::string_view s) {
+      auto as_int = Parse<int>::parse(s).value();
+      return as_int;
+    }
+};
+
 class ClapParser {
   public:
     void add_arg(const Arg& arg);

From 1bc25c8e6dcd94de313e4820023bc984b7665c3d Mon Sep 17 00:00:00 2001
From: csboo <csongiboo@gmail.com>
Date: Wed, 14 May 2025 03:03:09 +0200
Subject: [PATCH 2/6] feat(Parser): added a 'Parseable' c++ concept

---
 include/Parser.hpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/Parser.hpp b/include/Parser.hpp
index 302e229..4046498 100644
--- a/include/Parser.hpp
+++ b/include/Parser.hpp
@@ -39,6 +39,11 @@ struct Parse<bool> {
     }
 };
 
+template<typename T>
+concept Parseable = requires(std::string_view s) {
+    { Parse<T>::parse(s) } -> std::convertible_to<std::optional<T>>;
+};
+
 class ClapParser {
   public:
     void add_arg(const Arg& arg);

From 950d6575417c1e5fb4a85cb83f34acb9191176ca Mon Sep 17 00:00:00 2001
From: csboo <csongiboo@gmail.com>
Date: Wed, 14 May 2025 03:04:24 +0200
Subject: [PATCH 3/6] feat(Parser): parser uses way better parsing method!

---
 include/Parser.hpp | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/include/Parser.hpp b/include/Parser.hpp
index 4046498..3caf513 100644
--- a/include/Parser.hpp
+++ b/include/Parser.hpp
@@ -50,15 +50,19 @@ class ClapParser {
     void parse(const int& argc, char* argv[]);
     void print_help() const;
 
-    template <typename T> inline std::optional<T> get_one_as(const std::string& name) {
+    template <typename T>
+    requires Parseable<T>
+    inline std::optional<T> get_one_as(const std::string& name) {
         Arg* arg = ok_or(ClapParser::find_arg(*this, "--" + name), []{ return std::nullopt; });
 
-        if (auto arg_value = arg->get__value(); arg_value) {
-            T value;
-            std::istringstream(*arg_value) >> value;
-            return value;
-        }
-        return std::nullopt;
+        // if (auto arg_value = arg->get__value(); arg_value) {
+        //     T value;
+        //     std::istringstream(*arg_value) >> value;
+        //     return value;
+        // }
+        // return std::nullopt;
+
+        return Parse<T>::parse(arg->get__value().value());
     }
 
     static void print_parser(std::ostream& os, const ClapParser& parser, int indent);

From 0da288c6c481e10bae980d4d91847e0ecb1ee945 Mon Sep 17 00:00:00 2001
From: csboo <csongiboo@gmail.com>
Date: Wed, 14 May 2025 03:16:06 +0200
Subject: [PATCH 4/6] feat(Parser): impl Parse for (most) numeric types

---
 include/Parser.hpp | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/include/Parser.hpp b/include/Parser.hpp
index 3caf513..c2d69ff 100644
--- a/include/Parser.hpp
+++ b/include/Parser.hpp
@@ -11,16 +11,22 @@
 
 template<typename T>
 struct Parse {
-    static_assert(sizeof(T) == 0, "No Parse<T> specialization defined for this type");
-};
-
-template<>
-struct Parse<int> {
-    static std::optional<int> parse(std::string_view s) {
-        int value;
-        auto [ptr, ec] = std::from_chars(s.data(), s.data() + s.size(), value);
-        if (ec == std::errc()) return value;
-        return std::nullopt;
+    static std::optional<T> parse(std::string_view s) {
+        if constexpr (std::is_integral_v<T>) {
+            T value;
+            auto [ptr, ec] = std::from_chars(s.data(), s.data() + s.size(), value);
+            if (ec == std::errc()) return value;
+            return std::nullopt;
+        }
+        else if constexpr (std::is_floating_point_v<T>) {
+            T value;
+            auto [ptr, ec] = std::from_chars(s.data(), s.data() + s.size(), value);
+            if (ec == std::errc()) return value;
+            return std::nullopt;
+        }
+        else {
+            static_assert(sizeof(T) == 0, "No Parse<T> specialization defined for this type");
+        }
     }
 };
 

From 8545e16826c2f35710ca3792bad7d6e5c0ac659d Mon Sep 17 00:00:00 2001
From: csboo <csongiboo@gmail.com>
Date: Wed, 14 May 2025 03:19:28 +0200
Subject: [PATCH 5/6] fix(Parser): include 'charconv', remove 'cmath'

---
 include/Parser.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/Parser.hpp b/include/Parser.hpp
index c2d69ff..aea750e 100644
--- a/include/Parser.hpp
+++ b/include/Parser.hpp
@@ -3,7 +3,7 @@
 #include "Arg.hpp"
 #include "utils.hpp"
 
-#include <cmath>
+#include <charconv>
 #include <iostream>
 #include <optional>
 #include <string>

From fee7117ea8386988556c63031b66a62350510f5c Mon Sep 17 00:00:00 2001
From: csboo <csongiboo@gmail.com>
Date: Wed, 14 May 2025 03:27:11 +0200
Subject: [PATCH 6/6] fix(Parser): more explicit number casting for MacOS
 compatibility

---
 include/Parser.hpp | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/include/Parser.hpp b/include/Parser.hpp
index aea750e..dd7b0c7 100644
--- a/include/Parser.hpp
+++ b/include/Parser.hpp
@@ -3,6 +3,11 @@
 #include "Arg.hpp"
 #include "utils.hpp"
 
+#include <optional>
+#include <string_view>
+#include <type_traits>
+#include <system_error>
+#include <cstdlib>
 #include <charconv>
 #include <iostream>
 #include <optional>
@@ -18,10 +23,22 @@ struct Parse {
             if (ec == std::errc()) return value;
             return std::nullopt;
         }
-        else if constexpr (std::is_floating_point_v<T>) {
-            T value;
-            auto [ptr, ec] = std::from_chars(s.data(), s.data() + s.size(), value);
-            if (ec == std::errc()) return value;
+        else if constexpr (std::is_same_v<T, float>) {
+            char* end = nullptr;
+            float value = std::strtof(s.data(), &end);
+            if (end == s.data() + s.size()) return value;
+            return std::nullopt;
+        }
+        else if constexpr (std::is_same_v<T, double>) {
+            char* end = nullptr;
+            double value = std::strtod(s.data(), &end);
+            if (end == s.data() + s.size()) return value;
+            return std::nullopt;
+        }
+        else if constexpr (std::is_same_v<T, long double>) {
+            char* end = nullptr;
+            long double value = std::strtold(s.data(), &end);
+            if (end == s.data() + s.size()) return value;
             return std::nullopt;
         }
         else {