From 233d58c81a3b5bc9b6d01d4555302d588d9f3e59 Mon Sep 17 00:00:00 2001
From: Sandipan Mohanty <s.mohanty@fz-juelich.de>
Date: Fri, 13 May 2022 12:00:33 +0200
Subject: [PATCH] Provide range_output.hh
---
code/include/range_output.hh | 113 +++++++++++++++++++++++++++++++++++
1 file changed, 113 insertions(+)
create mode 100644 code/include/range_output.hh
diff --git a/code/include/range_output.hh b/code/include/range_output.hh
new file mode 100644
index 0000000..65508ea
--- /dev/null
+++ b/code/include/range_output.hh
@@ -0,0 +1,113 @@
+#pragma once
+#include <algorithm>
+#include <iomanip>
+#include <iosfwd>
+#include <cxx20ranges>
+#include <string>
+
+namespace output {
+template <class C>
+concept RawArray = std::is_array_v<C>;
+template <class C>
+concept ArrayClass = requires(C c)
+{
+ { c[1ul] };
+ { c.size() };
+};
+
+template <class C>
+concept StringLike = std::convertible_to<C, std::string_view>;
+
+namespace {
+ //auto size(const Container auto& C) { return C.size(); }
+ auto size(const RawArray auto& C) { return std::extent_v<std::remove_cvref_t<decltype(C)>>; }
+}
+
+template <class C>
+concept ArrayLike = (not StringLike<C>)and(ArrayClass<C> or RawArray<C>);
+
+template <class T>
+void write_possibly_quoted(std::ostream& os, T&& t)
+{
+ if constexpr (StringLike<T>) {
+ os << std::quoted(t);
+ } else {
+ os << t;
+ }
+}
+
+std::ostream& operator<<(std::ostream& os, const ArrayLike auto& c)
+{
+ os << "[";
+ auto sz = size(c);
+ for (size_t i {}; i != sz; ++i) {
+ write_possibly_quoted(os, c[i]);
+ if (i + 1 < sz)
+ os << ", ";
+ }
+ return os << "]";
+}
+
+template <class T>
+requires(not StringLike<T> and sr::range<T>)
+ std::ostream&
+ operator<<(std::ostream& os, T&& r)
+{
+ os << "[";
+ for (auto el : r) {
+ write_possibly_quoted(os, el);
+ os << ", ";
+ }
+ return os << "]";
+}
+template <class SepType>
+class rprinter {
+ std::ostream* strmptr = nullptr;
+ SepType sep;
+
+public:
+ rprinter(SepType s)
+ : sep { s }
+ {
+ }
+ rprinter(const rprinter&) noexcept = default;
+ std::ostream& stream() { return *strmptr; }
+ void stream(std::ostream& os) { strmptr = &os; }
+ const auto& separator() const noexcept { return sep; }
+};
+template <>
+class rprinter<void> {
+ std::ostream* strmptr = nullptr;
+
+public:
+ std::ostream& stream() { return *strmptr; }
+ void stream(std::ostream& os) { strmptr = &os; }
+};
+
+template <class T>
+rprinter<T> operator<<(std::ostream& os, rprinter<T> r)
+{
+ r.stream(os);
+ return { r };
+}
+template <class T>
+std::ostream& operator<<(rprinter<T> vp, sr::range auto&& t)
+{
+ if constexpr (std::is_same_v<T, void>) {
+ for (auto&& el : t)
+ vp.stream() << el;
+ } else {
+ if (not sr::empty(t)) {
+ vp.stream() << *sr::begin(t);
+ sr::for_each(t | sv::drop(1), [&vp](auto&& el) {
+ vp.stream() << vp.separator() << el;
+ });
+ }
+ }
+ return vp.stream();
+}
+
+inline rprinter<void> unseparated;
+inline rprinter<const char*> comma_separated { ", " };
+
+}
--
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