Introducing buildprint, a type-safe and more performant replacement for printf using C++11 variadic templates. At least, an incomplete version that is enough to implement the next commit.

git-svn-id: https://svn.eduke32.com/eduke32@6139 1a8010ca-5511-0410-912e-c29ae57300e0

source/build/include/baselayer.h

@@ -249,5 +249,7 @@ void maybe_redirect_outputs(void);
 }
 #endif
 
+#include "print.h"
+
 #endif // baselayer_h_
 

source/build/include/print.h

@@ -0,0 +1,194 @@
+
+#pragma once
+
+#ifndef print_h_
+#define print_h_
+
+#if CXXSTD >= 2011
+
+template <typename T>
+struct binwrap
+{
+    T data;
+};
+template <typename T>
+static FORCE_INLINE constexpr binwrap<T> bin(T x)
+{
+    return binwrap<T>{x};
+}
+template <typename T>
+struct octwrap
+{
+    T data;
+};
+template <typename T>
+static FORCE_INLINE constexpr octwrap<T> oct(T x)
+{
+    return octwrap<T>{x};
+}
+template <typename T>
+struct hexwrap
+{
+    T data;
+};
+template <typename T>
+static FORCE_INLINE constexpr hexwrap<T> hex(T x)
+{
+    return hexwrap<T>{x};
+}
+template <typename T>
+struct HEXwrap
+{
+    T data;
+};
+template <typename T>
+static FORCE_INLINE constexpr HEXwrap<T> HEX(T x)
+{
+    return HEXwrap<T>{x};
+}
+
+FORCE_INLINE constexpr size_t buildprintpiece(void)
+{
+    return 0;
+}
+
+template<typename T>
+enable_if_t<is_integral<T>::value, size_t> buildprintpiece(T x)
+{
+    // log_10(2^x) = x * log(2)/log(10) ~= x * 0.30103
+    size_t constexpr numdigits = (sizeof(T) * CHAR_BIT + 1) / 3;
+    char str[numdigits + 2]; // +2 for '-', '\0'
+
+    char * strptr = str;
+
+    size_t totalChars;
+    if (x < 0)
+    {
+        size_t numChars = logbasenegative<10>(x);
+        totalChars = numChars+1;
+        *strptr++ = '-';
+        strptr[numChars] = '\0';
+        do
+        {
+            DivResult<T> const qr = divrhs<10>(x);
+            x = qr.q;
+            strptr[numChars-1] = '0' - (char)qr.r;
+        }
+        while (--numChars);
+    }
+    else
+    {
+        size_t numChars = logbase<10>(x);
+        totalChars = numChars;
+        strptr[numChars] = '\0';
+        do
+        {
+            DivResult<T> const qr = divrhs<10>(x);
+            x = qr.q;
+            strptr[numChars-1] = '0' + (char)qr.r;
+        }
+        while (--numChars);
+    }
+
+    initputs(str);
+    return totalChars;
+}
+
+template<typename T>
+enable_if_t<is_integral<T>::value, size_t> buildprintpiece(binwrap<T> x)
+{
+    make_unsigned_t<T> const data = x.data;
+
+    size_t constexpr numChars = sizeof(x)*CHAR_BIT;
+    char str[numChars+1];
+    str[numChars] = '\0';
+
+    for (size_t p = 0; p < numChars; ++p)
+        str[numChars - 1 - p] = '0' + (char)((data >> p) & 1);
+
+    initputs(str);
+    return numChars;
+}
+
+template<typename T>
+enable_if_t<is_integral<T>::value, size_t> buildprintpiece(octwrap<T> x)
+{
+    make_unsigned_t<T> const data = x.data;
+
+    size_t constexpr numChars = (sizeof(x)*CHAR_BIT + 2) / 3;
+    char str[numChars+1];
+    str[numChars] = '\0';
+
+    for (size_t p = 0; p < numChars; ++p)
+        str[numChars - 1 - p] = '0' + (char)((data >> (p*3)) & 7);
+
+    initputs(str);
+    return numChars;
+}
+
+template<typename T>
+enable_if_t<is_integral<T>::value, size_t> buildprintpiece(hexwrap<T> x)
+{
+    static char const hexletters[] = "0123456789abcdef";
+
+    make_unsigned_t<T> const data = x.data;
+
+    size_t constexpr numChars = (sizeof(x)*CHAR_BIT + 3) / 4;
+    char str[numChars+1];
+    str[numChars] = '\0';
+
+    for (size_t p = 0; p < numChars; ++p)
+        str[numChars - 1 - p] = hexletters[(size_t)((data >> (p*4)) & 0xF)];
+
+    initputs(str);
+    return numChars;
+}
+
+template<typename T>
+enable_if_t<is_integral<T>::value, size_t> buildprintpiece(HEXwrap<T> x)
+{
+    static char const HEXletters[] = "0123456789ABCDEF";
+
+    make_unsigned_t<T> const data = x.data;
+
+    size_t constexpr numChars = (sizeof(x)*CHAR_BIT + 3) / 4;
+    char str[numChars+1];
+    str[numChars] = '\0';
+
+    for (size_t p = 0; p < numChars; ++p)
+        str[numChars - 1 - p] = HEXletters[(size_t)((data >> (p*4)) & 0xF)];
+
+    initputs(str);
+    return numChars;
+}
+
+template <typename T>
+FORCE_INLINE size_t buildprintpiece(const T * x)
+{
+    return buildprintpiece(hex((uintptr_t)x));
+}
+
+FORCE_INLINE size_t buildprintpiece(char const *str)
+{
+    initputs(str);
+    return strlen(str);
+}
+
+template<typename T>
+static FORCE_INLINE size_t buildprint(T first)
+{
+    return buildprintpiece(first);
+}
+
+template<typename T, typename... Args>
+size_t buildprint(T first, Args... args)
+{
+    size_t const len = buildprintpiece(first);
+    return len + buildprint(args...);
+}
+
+// this file is incomplete. a fuller implementation exists but has not been completed and debugged.
+
+#endif
+
+#endif // print_h_