[C++] The first commit for C++ version

16 tests out of 169 are passing.

1 files changed, 22 insertions, 0 deletions

diff --git a/stringprintf.cc b/stringprintf.cc
new file mode 100644
index 0000000..d4fe74f
--- /dev/null
+++ b/stringprintf.cc
@@ -0,0 +1,22 @@
+#include "stringprintf.h"
+
+#include <assert.h>
+#include <stdarg.h>
+
+string StringPrintf(const char* format, ...) {
+  string str;
+  str.resize(128);
+  for (int i = 0; i < 2; i++) {
+    va_list args;
+    va_start(args, format);
+    int ret = vsnprintf(&str[0], str.size(), format, args);
+    va_end(args);
+    assert(ret >= 0);
+    if (static_cast<size_t>(ret) < str.size()) {
+      str.resize(ret);
+      return str;
+    }
+    str.resize(ret + 1);
+  }
+  assert(false);
+}