Introduce ctl::to_string()

ctl/to_string.cc

@@ -0,0 +1,109 @@
+// -*- mode:c++; indent-tabs-mode:nil; c-basic-offset:4; coding:utf-8 -*-
+// vi: set et ft=cpp ts=4 sts=4 sw=4 fenc=utf-8 :vi
+//
+// Copyright 2024 Justine Alexandra Roberts Tunney
+//
+// Permission to use, copy, modify, and/or distribute this software for
+// any purpose with or without fee is hereby granted, provided that the
+// above copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include "dubble.h"
+#include "libc/fmt/itoa.h"
+#include "libc/math.h"
+#include "string.h"
+#include "third_party/gdtoa/gdtoa.h"
+
+namespace ctl {
+
+extern const double_conversion::DoubleToStringConverter kDoubleToPrintfG;
+
+string
+to_string(int value)
+{
+    char buf[12];
+    return { buf, FormatInt32(buf, value) - buf };
+}
+
+string
+to_string(unsigned value)
+{
+    char buf[12];
+    return { buf, FormatUint32(buf, value) - buf };
+}
+
+string
+to_string(long value)
+{
+    char buf[21];
+    return { buf, FormatInt64(buf, value) - buf };
+}
+
+string
+to_string(unsigned long value)
+{
+    char buf[21];
+    return { buf, FormatUint64(buf, value) - buf };
+}
+
+string
+to_string(long long value)
+{
+    char buf[21];
+    return { buf, FormatInt64(buf, value) - buf };
+}
+
+string
+to_string(unsigned long long value)
+{
+    char buf[21];
+    return { buf, FormatUint64(buf, value) - buf };
+}
+
+string
+to_string(float value)
+{
+    char buf[128];
+    double_conversion::StringBuilder b(buf, sizeof(buf));
+    kDoubleToPrintfG.ToShortestSingle(value, &b);
+    b.Finalize();
+    return string(buf);
+}
+
+string
+to_string(double value)
+{
+    char buf[128];
+    double_conversion::StringBuilder b(buf, sizeof(buf));
+    kDoubleToPrintfG.ToShortest(value, &b);
+    b.Finalize();
+    return string(buf);
+}
+
+string
+to_string(long double value)
+{
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+    return to_string((double)value);
+#else
+    char buf[128];
+#if LDBL_MANT_DIG == 113
+    g_Qfmt_p(buf, &value, 16, 128, NIK(2, 0, 0));
+#elif LDBL_MANT_DIG == 64
+    g_xfmt_p(buf, &value, 16, 128, NIK(2, 0, 0));
+#else
+#error "unsupported long double"
+#endif
+    return string(buf);
+#endif
+}
+
+} // namespace ctl