From 3e683a243635435c47ee4c60ba2492333a052a72 Mon Sep 17 00:00:00 2001
From: q66 <daniel@octaforge.org>
Date: Wed, 1 Feb 2017 19:29:42 +0100
Subject: [PATCH] remove silly intermediate ranges for writef, print directly
 to stream

---
 ostd/io.hh     | 32 +++++++++++++++-----------------
 ostd/stream.hh | 47 ++++++-----------------------------------------
 2 files changed, 21 insertions(+), 58 deletions(-)

diff --git a/ostd/io.hh b/ostd/io.hh
index d819209..26ddc8c 100644
--- a/ostd/io.hh
+++ b/ostd/io.hh
@@ -165,6 +165,17 @@ namespace detail {
     ) {
         write_impl(ostd::to_string(v));
     }
+
+    /* lightweight output range for direct stdout */
+    struct StdoutRange: OutputRange<StdoutRange, char> {
+        StdoutRange() {}
+        bool put(char c) {
+            return putchar(c) != EOF;
+        }
+        size_t put_n(char const *p, size_t n) {
+            return fwrite(p, 1, n, stdout);
+        }
+    };
 }
 
 template<typename T>
@@ -181,38 +192,25 @@ inline void write(T const &v, A const &...args) {
 template<typename T>
 inline void writeln(T const &v) {
     write(v);
-    putc('\n', stdout);
+    putchar('\n');
 }
 
 template<typename T, typename ...A>
 inline void writeln(T const &v, A const &...args) {
     write(v);
     write(args...);
-    putc('\n', stdout);
+    putchar('\n');
 }
 
 template<typename ...A>
 inline void writef(ConstCharRange fmt, A const &...args) {
-    char buf[512];
-    ptrdiff_t need = format(
-        detail::FormatOutRange<sizeof(buf)>(buf), fmt, args...
-    );
-    if (need < 0) {
-        return;
-    } else if (size_t(need) < sizeof(buf)) {
-        fwrite(buf, 1, need, stdout);
-        return;
-    }
-    std::vector<char> s;
-    s.reserve(need);
-    format(detail::UnsafeWritefRange(s.data()), fmt, args...);
-    fwrite(s.data(), 1, need, stdout);
+    format(detail::StdoutRange{}, fmt, args...);
 }
 
 template<typename ...A>
 inline void writefln(ConstCharRange fmt, A const &...args) {
     writef(fmt, args...);
-    putc('\n', stdout);
+    putchar('\n');
 }
 
 } /* namespace ostd */
diff --git a/ostd/stream.hh b/ostd/stream.hh
index 3e489ad..8485608 100644
--- a/ostd/stream.hh
+++ b/ostd/stream.hh
@@ -35,32 +35,6 @@ enum class StreamSeek {
 template<typename T = char, bool = IsPod<T>>
 struct StreamRange;
 
-namespace detail {
-    template<size_t N>
-    struct FormatOutRange: OutputRange<FormatOutRange<N>, char> {
-        FormatOutRange(char *ibuf): buf(ibuf), idx(0) {}
-        FormatOutRange(FormatOutRange const &r): buf(r.buf), idx(r.idx) {}
-        char *buf;
-        size_t idx;
-        bool put(char v) {
-            if (idx < N) {
-                buf[idx++] = v;
-                return true;
-            }
-            return false;
-        }
-    };
-
-    struct UnsafeWritefRange: OutputRange<UnsafeWritefRange, char> {
-        UnsafeWritefRange(char *p): p_ptr(p) {}
-        bool put(char c) {
-            *p_ptr++ = c;
-            return true;
-        }
-        char *p_ptr;
-    };
-}
-
 struct Stream {
 private:
     struct StNat {};
@@ -138,21 +112,7 @@ public:
     }
 
     template<typename ...A>
-    bool writef(ConstCharRange fmt, A const &...args) {
-        char buf[512];
-        ptrdiff_t need = format(
-            detail::FormatOutRange<sizeof(buf)>(buf), fmt, args...
-        );
-        if (need < 0) {
-            return false;
-        } else if (size_t(need) < sizeof(buf)) {
-            return write_bytes(buf, need) == size_t(need);
-        }
-        std::vector<char> s;
-        s.reserve(need);
-        format(detail::UnsafeWritefRange(s.data()), fmt, args...);
-        return write_bytes(s.data(), need) == size_t(need);
-    }
+    bool writef(ConstCharRange fmt, A const &...args);
 
     template<typename ...A>
     bool writefln(ConstCharRange fmt, A const &...args) {
@@ -246,6 +206,11 @@ inline StreamRange<T> Stream::iter() {
     return StreamRange<T>(*this);
 }
 
+template<typename ...A>
+inline bool Stream::writef(ConstCharRange fmt, A const &...args) {
+    return format(iter(), fmt, args...) >= 0;
+}
+
 }
 
 #endif