From 14b85d9cb6c4da5f0abc4544b348ffd51b698969 Mon Sep 17 00:00:00 2001
From: John Sallay <jasallay@gmail.com>
Date: Fri, 5 Jul 2024 21:27:25 -0400
Subject: [PATCH] Need to use std::visit to make compiler happy

---
 include/pmtv/format.hpp | 53 +++++++++++++----------------------------
 meson.build             |  2 +-
 2 files changed, 18 insertions(+), 37 deletions(-)

diff --git a/include/pmtv/format.hpp b/include/pmtv/format.hpp
index dd770d8..dc5dc3d 100644
--- a/include/pmtv/format.hpp
+++ b/include/pmtv/format.hpp
@@ -45,42 +45,23 @@ struct formatter<P>
 
     template <typename FormatContext>
     auto format(const P& value, FormatContext& ctx) const {
-        // Using visit here is fairly slow.  It is probably because of the recursive nature of it.
-        // It is really simple to enumerate the possibilities here.
-        using namespace pmtv;
-        if (std::holds_alternative<std::monostate>(value)) return fmt::format_to(ctx.out(), "null");
-        else if (std::holds_alternative<bool>(value)) return fmt::format_to(ctx.out(), "{}", std::get<bool>(value));
-        else if (std::holds_alternative<uint8_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<uint8_t>(value));
-        else if (std::holds_alternative<uint16_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<uint16_t>(value));
-        else if (std::holds_alternative<uint32_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<uint32_t>(value));
-        else if (std::holds_alternative<uint64_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<uint64_t>(value));
-        else if (std::holds_alternative<int8_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<int8_t>(value));
-        else if (std::holds_alternative<int16_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<int16_t>(value));
-        else if (std::holds_alternative<int32_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<int32_t>(value));
-        else if (std::holds_alternative<int64_t>(value)) return fmt::format_to(ctx.out(), "{}", std::get<int64_t>(value));
-        else if (std::holds_alternative<float>(value)) return fmt::format_to(ctx.out(), "{}", std::get<float>(value));
-        else if (std::holds_alternative<double>(value)) return fmt::format_to(ctx.out(), "{}", std::get<double>(value));
-        else if (std::holds_alternative<std::complex<float>>(value)) return fmt::format_to(ctx.out(), "{}", std::get<std::complex<float>>(value));
-        else if (std::holds_alternative<std::complex<double>>(value)) return fmt::format_to(ctx.out(), "{}", std::get<std::complex<double>>(value));
-        else if (std::holds_alternative<std::vector<bool>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<bool>>(value), ", "));
-        else if (std::holds_alternative<std::vector<uint8_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<uint8_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<uint16_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<uint16_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<uint32_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<uint32_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<uint64_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<uint64_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<int8_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<int8_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<int16_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<int16_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<int32_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<int32_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<int64_t>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<int64_t>>(value), ", "));
-        else if (std::holds_alternative<std::vector<float>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<float>>(value), ", "));
-        else if (std::holds_alternative<std::vector<double>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<double>>(value), ", "));
-        else if (std::holds_alternative<std::vector<std::complex<float>>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<std::complex<float>>>(value), ", "));
-        else if (std::holds_alternative<std::vector<std::complex<double>>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<std::complex<double>>>(value), ", "));
-        else if (std::holds_alternative<std::string>(value)) return fmt::format_to(ctx.out(), "{}", std::get<std::string>(value));
-        else if (std::holds_alternative<std::vector<std::string>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<std::string>>(value), ", "));
-        else if (std::holds_alternative<std::vector<pmt>>(value)) return fmt::format_to(ctx.out(), "[{}]", fmt::join(std::get<std::vector<pmt>>(value), ", "));
-        else if (std::holds_alternative<map_t>(value)) return fmt::format_to(ctx.out(), "{{{}}}", fmt::join(std::get<map_t>(value), ", "));
-        //static_assert(false);
-        return fmt::format_to(ctx.out(), "error");
+        return std::visit([&ctx](const auto arg) {
+            using namespace pmtv;
+            using T = std::decay_t<decltype(arg)>;
+            if constexpr (Scalar<T> || Complex<T>)
+                return fmt::format_to(ctx.out(), "{}", arg);
+            else if constexpr (std::same_as<T, std::string>)
+                return fmt::format_to(ctx.out(), "{}",  arg);
+            else if constexpr (UniformVector<T> || UniformStringVector<T>)
+                return fmt::format_to(ctx.out(), "[{}]", fmt::join(arg, ", "));
+            else if constexpr (std::same_as<T, std::vector<pmt>>) {
+                return fmt::format_to(ctx.out(), "[{}]", fmt::join(arg, ", "));
+            } else if constexpr (PmtMap<T>) {
+                return fmt::format_to(ctx.out(), "{{{}}}", fmt::join(arg, ", "));
+            } else if constexpr (std::same_as<std::monostate, T>)
+                return fmt::format_to(ctx.out(), "null");
+            return fmt::format_to(ctx.out(), "unknown type {}", typeid(T).name());
+            }, value);
 
     }
 };
diff --git a/meson.build b/meson.build
index 8b1d886..08bd4f2 100644
--- a/meson.build
+++ b/meson.build
@@ -2,7 +2,7 @@ project('pmt', 'cpp',
   version : '0.0.2',
   meson_version: '>=0.63.0',
   license : 'GPLv3',
-  default_options : ['cpp_std=c++20', 'warning_level=3'])
+  default_options : ['cpp_std=c++23', 'warning_level=3'])
 
 cc = meson.get_compiler('cpp')
 warnings_as_errors = get_option('warnings_as_errors') # Define this option in your meson_options.txt