core: implement String::Printf() and start working on the unit tests.

I'm gonna commit this right now though I'm not really sure whether Visual
Studio will agree to build va_copy and others.

src/Makefile.am

@@ -40,7 +40,7 @@ liblol_a_SOURCES = \
     $(android_sources) \
     $(bullet_sources) \
     \
-    core/hash.cpp \
+    core/hash.cpp core/string.cpp \
     \
     thread/threadbase.h thread/thread.h \
     \

src/core/string.cpp

@@ -0,0 +1,51 @@
+//
+// Lol Engine
+//
+// Copyright: (c) 2010-2012 Sam Hocevar <sam@hocevar.net>
+//   This program is free software; you can redistribute it and/or
+//   modify it under the terms of the Do What The Fuck You Want To
+//   Public License, Version 2, as published by Sam Hocevar. See
+//   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
+//
+
+#if defined HAVE_CONFIG_H
+#   include "config.h"
+#endif
+
+#include <cstdio>
+
+#ifdef WIN32
+#   define WIN32_LEAN_AND_MEAN
+#   include <windows.h>
+#endif
+
+#include <cstdarg>
+
+#include "core.h"
+
+namespace lol
+{
+
+String String::Printf(char const *format, ...)
+{
+    String ret;
+
+    va_list ap, aq;
+    va_start(ap, format);
+    va_copy(aq, ap);
+
+    /* vsnprintf() tells us how many character we need, and we need to
+     * add one for the terminating null byte. */
+    size_t needed = vsnprintf(NULL, 0, format, aq) + 1;
+    ((Super &)ret).Reserve(needed);
+    ret.m_count = needed;
+    vsnprintf(&ret[0], needed, format, ap);
+
+    va_end(aq);
+    va_end(ap);
+
+    return ret;
+}
+
+} /* namespace lol */
+

src/lol/core/string.h

@@ -70,7 +70,7 @@ public:
         return ret += s;
     }
 
-    inline String operator +=(String const &s)
+    inline String& operator +=(String const &s)
     {
         /* Be careful, we have a trailing zero we don't want! */
         --m_count;
@@ -84,7 +84,7 @@ public:
         return ret += c;
     }
 
-    inline String operator +=(char c)
+    inline String& operator +=(char c)
     {
         ((Super &)*this).Last() = c;
         ((Super &)*this).Push('\0');
@@ -107,6 +107,14 @@ public:
     {
         return !(*this == s);
     }
+
+#ifdef __GNUC__
+#   define LOL_FMT_ATTR(n, p) __attribute__((format(printf, n, p)))
+#else
+#   define LOL_FMT_ATTR(n, p)
+#endif
+    static String Printf(char const *format, ...) LOL_FMT_ATTR(1, 2);
+#undef LOL_FMT_ATTR
 };
 
 } /* namespace lol */

src/lolcore.vcxproj

@@ -235,6 +235,7 @@
     <ClCompile Include="bullet\LinearMath\btSerializer.cpp" />
     <ClCompile Include="camera.cpp" />
     <ClCompile Include="core\hash.cpp" />
+    <ClCompile Include="core\string.cpp" />
     <ClCompile Include="debug\fps.cpp" />
     <ClCompile Include="debug\record.cpp" />
     <ClCompile Include="debug\stats.cpp" />

src/lolcore.vcxproj.filters

@@ -11,6 +11,9 @@
     <Filter Include="src\debug">
       <UniqueIdentifier>{e056731c-5484-434a-965e-801c199c0366}</UniqueIdentifier>
     </Filter>
+    <Filter Include="src\core">
+      <UniqueIdentifier>{a63b1fd6-3747-4a9f-9bd7-3f942133ad6b}</UniqueIdentifier>
+    </Filter>
     <Filter Include="src\platform">
       <UniqueIdentifier>{a11c55f8-8e10-4270-be24-38e8d4fcf589}</UniqueIdentifier>
     </Filter>
@@ -179,7 +182,10 @@
       <Filter>src\...</Filter>
     </ClCompile>
     <ClCompile Include="hash.cpp">
-      <Filter>src\...</Filter>
+      <Filter>src\core</Filter>
+    </ClCompile>
+    <ClCompile Include="string.cpp">
+      <Filter>src\core</Filter>
     </ClCompile>
     <ClCompile Include="layer.cpp">
       <Filter>src\...</Filter>

test/unit/string.cpp

@@ -120,6 +120,14 @@ LOLUNIT_FIXTURE(StringTest)
         LOLUNIT_ASSERT(s1 != s2);
         LOLUNIT_ASSERT(!(s1 != s3));
     }
+
+    LOLUNIT_TEST(StringPrintf)
+    {
+        String s1 = "3a";
+        String s2 = String::Printf("%d%x", 3, 10);
+
+        LOLUNIT_ASSERT(s1 == s2);
+    }
 };
 
 } /* namespace lol */