From 537bdc5e1975e045100ed8bef367cec1fe720013 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 19 Mar 2020 15:13:02 -0700
Subject: [PATCH] ircd::json: Add tuple get()/at() non-constexpr accessor
 suite.

---
 include/ircd/json/tuple/at.h    | 58 +++++++++++++++++++++++++++++++++
 include/ircd/json/tuple/get.h   | 22 +++++++++++++
 include/ircd/json/tuple/tuple.h | 38 +++++++++++++++++++--
 3 files changed, 116 insertions(+), 2 deletions(-)

diff --git a/include/ircd/json/tuple/at.h b/include/ircd/json/tuple/at.h
index ce0c9a5a1..7a77eb2a7 100644
--- a/include/ircd/json/tuple/at.h
+++ b/include/ircd/json/tuple/at.h
@@ -126,5 +126,63 @@ at(const tuple &t,
 		at<tuple, function, i + 1>(t, name, std::forward<function>(f));
 }
 
+template<class R,
+         class tuple>
+enable_if_tuple<tuple, const R &>
+at(const tuple &t,
+   const string_view &name)
+{
+	const R *ret;
+	const auto closure
+	{
+		[&name, &ret](const auto &key, const auto &val)
+		{
+			if(key == name)
+			{
+				ret = std::addressof(val);
+				return false;
+			}
+			else return true;
+		}
+	};
+
+	if(unlikely(until(t, closure)))
+		throw not_found
+		{
+			"%s", name
+		};
+
+	return *ret;
+}
+
+template<class R,
+         class tuple>
+enable_if_tuple<tuple, R &>
+at(tuple &t,
+   const string_view &name)
+{
+	R *ret;
+	const auto closure
+	{
+		[&name, &ret](const auto &key, auto &val)
+		{
+			if(key == name)
+			{
+				ret = std::addressof(val);
+				return false;
+			}
+			else return true;
+		}
+	};
+
+	if(unlikely(until(t, closure)))
+		throw not_found
+		{
+			"%s", name
+		};
+
+	return *ret;
+}
+
 } // namespace json
 } // namespace ircd
diff --git a/include/ircd/json/tuple/get.h b/include/ircd/json/tuple/get.h
index a92b9b3cf..56cb2d171 100644
--- a/include/ircd/json/tuple/get.h
+++ b/include/ircd/json/tuple/get.h
@@ -125,5 +125,27 @@ noexcept
 	return get<name_hash(name), tuple>(t, def);
 }
 
+template<class R,
+         class tuple>
+enable_if_tuple<tuple, R>
+get(const tuple &t,
+    const string_view &name,
+    R ret)
+noexcept
+{
+	until(t, [&name, &ret]
+	(const auto &key, auto&& val)
+	{
+		if(key == name)
+		{
+			ret = val;
+			return false;
+		}
+		else return true;
+	});
+
+	return ret;
+}
+
 } // namespace json
 } // namespace ircd
diff --git a/include/ircd/json/tuple/tuple.h b/include/ircd/json/tuple/tuple.h
index 994183012..1ae2711c6 100644
--- a/include/ircd/json/tuple/tuple.h
+++ b/include/ircd/json/tuple/tuple.h
@@ -67,6 +67,10 @@ struct tuple
 	template<class name> constexpr decltype(auto) at(name&&) const;
 	template<class name> constexpr decltype(auto) at(name&&);
 
+	template<class R, class name> R get(name&&, R def = {}) const noexcept;
+	template<class R, class name> const R &at(name&&) const;
+	template<class R, class name> R &at(name&&);
+
 	template<class... U> explicit tuple(const tuple<U...> &);
 	template<class U> explicit tuple(const json::object &, const json::keys<U> &);
 	template<class U> explicit tuple(const tuple &, const json::keys<U> &);
@@ -166,10 +170,10 @@ key_exists(const string_view &key)
 } // namespace json
 } // namespace ircd
 
-#include "get.h"
-#include "at.h"
 #include "for_each.h"
 #include "until.h"
+#include "get.h"
+#include "at.h"
 #include "set.h"
 
 namespace ircd {
@@ -297,6 +301,36 @@ const noexcept
 	return json::get<hash>(*this);
 }
 
+template<class... T>
+template<class R,
+         class name>
+R
+tuple<T...>::get(name&& n,
+                 R ret)
+const noexcept
+{
+	return json::get<R>(*this, n, ret);
+}
+
+template<class... T>
+template<class R,
+         class name>
+const R &
+tuple<T...>::at(name&& n)
+const
+{
+	return json::at<R>(*this, n);
+}
+
+template<class... T>
+template<class R,
+         class name>
+R &
+tuple<T...>::at(name&& n)
+{
+	return json::at<R>(*this, n);
+}
+
 template<class... T>
 constexpr size_t
 tuple<T...>::size()