string: add snprintf

Signed-off-by: Simon Rozman <simon@rozman.si>

UnitTests/main.cpp

@@ -28,6 +28,7 @@ int main(int, const char *[])
 		UnitTests::stream::replicator();
 		UnitTests::string::strncpy();
 		UnitTests::string::sprintf();
+		UnitTests::string::snprintf();
 		UnitTests::unicode::charset_encoder();
 		UnitTests::unicode::normalize();
 		UnitTests::unicode::str2wstr();

UnitTests/pch.hpp

@@ -109,6 +109,7 @@ namespace UnitTests
 	public:
 		TEST_METHOD(strncpy);
 		TEST_METHOD(sprintf);
+		TEST_METHOD(snprintf);
 	};
 
 	TEST_CLASS(unicode)

UnitTests/string.cpp

@@ -42,4 +42,31 @@ namespace UnitTests
 		Assert::AreEqual(str.c_str(), stdex::sprintf("%s", locale, str.data()).c_str());
 		Assert::AreEqual(str.size(), stdex::sprintf("%s", locale, str.data()).size());
 	}
+
+	void string::snprintf()
+	{
+		stdex::locale locale(stdex::create_locale(LC_ALL, "en_US.UTF-8"));
+
+		{
+			wchar_t buf[0x100];
+			Assert::IsTrue(stdex::snprintf(buf, _countof(buf), L"This is %ls.", locale, L"a test") == 15);
+			Assert::AreEqual(L"This is a test.", buf);
+		}
+		{
+			char buf[0x100];
+			Assert::IsTrue(stdex::snprintf(buf, _countof(buf), "This is %s.", locale, "a test") == 15);
+			Assert::AreEqual("This is a test.", buf);
+		}
+
+		{
+			wchar_t buf[8];
+			Assert::IsTrue(stdex::snprintf(buf, _countof(buf), L"This is %ls.", locale, L"a test") == 8);
+			Assert::IsTrue(stdex::strncmp(L"This is a test.", buf, _countof(buf)) == 0);
+		}
+		{
+			char buf[8];
+			Assert::IsTrue(stdex::snprintf(buf, _countof(buf), "This is %s.", locale, "a test") == 8);
+			Assert::IsTrue(stdex::strncmp("This is a test.", buf, _countof(buf)) == 0);
+		}
+	}
 }

include/stdex/sgml.hpp

@@ -620,7 +620,7 @@ namespace stdex
 						dst.append(1, static_cast<char>(src[i++]));
 					else {
 						char tmp[3 + 8 + 1 + 1];
-						snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(src[i++]));
+						::snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(src[i++]));
 						dst.append(tmp);
 					}
 				}
@@ -638,7 +638,7 @@ namespace stdex
 							dst.append(1, static_cast<char>(src[i++]));
 						else {
 							char tmp[3 + 8 + 1 + 1];
-							snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(wstr_to_utf32(src, i, end)));
+							::snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(wstr_to_utf32(src, i, end)));
 							dst.append(tmp);
 						}
 					}
@@ -742,7 +742,7 @@ namespace stdex
 					}
 					else {
 						char tmp[3 + 8 + 1 + 1];
-						int m = snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(src[i++]));
+						int m = ::snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(src[i++]));
 						stdex_assert(m >= 0);
 						if (static_cast<size_t>(m) >= count_dst)
 							throw buffer_overrun;
@@ -770,7 +770,7 @@ namespace stdex
 						}
 						else {
 							char tmp[3 + 8 + 1 + 1];
-							int m = snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(wstr_to_utf32(src, i, end)));
+							int m = ::snprintf(tmp, _countof(tmp), "&#x%x;", static_cast<unsigned int>(wstr_to_utf32(src, i, end)));
 							stdex_assert(m >= 0);
 							if (static_cast<size_t>(m) >= count_dst)
 								throw buffer_overrun;

include/stdex/string.hpp

@@ -2655,6 +2655,45 @@ namespace stdex
 	}
 	/// \endcond
 
+	///
+	/// Formats string using `printf()`.
+	///
+	/// \param[out] str       Output string
+	/// \param[in ] capacity  Number of available code units in str
+	/// \param[in ] format    String template using `printf()` style
+	/// \param[in ] locale    Stdlib locale used to perform formatting. Use `NULL` to use locale globally set by `setlocale()`.
+	///
+	/// \return Number of output code units
+	///
+	template<class T>
+	inline size_t snprintf(_Out_z_cap_(capacity) T* str, _In_ size_t capacity, _In_z_ _Printf_format_string_params_(2) const T* format, _In_opt_ locale_t locale, ...)
+	{
+		va_list arg;
+		va_start(arg, locale);
+		int count = vsnprintf(str, capacity, format, locale, arg);
+		va_end(arg);
+		if (0 <= count && static_cast<size_t>(count) <= capacity)
+			return static_cast<size_t>(count);
+#ifdef _WIN32
+		if (count < 0) {
+			switch (errno) {
+			case 0: return capacity;
+			case EINVAL: throw std::invalid_argument("invalid snprintf arguments");
+			case EILSEQ: throw std::runtime_error("encoding error");
+			default: throw std::runtime_error("failed to format string");
+			}
+		} else
+			return capacity;
+#else
+		switch (errno) {
+		case EOVERFLOW: return capacity;
+		case EINVAL: throw std::invalid_argument("invalid snprintf arguments");
+		case EILSEQ: throw std::runtime_error("encoding error");
+		default: throw std::runtime_error("failed to format string");
+		}
+#endif
+	}
+
 	///
 	/// Formats string using `printf()`.
 	///

include/stdex/uuid.hpp

@@ -43,7 +43,7 @@ namespace stdex
 			static_cast<unsigned int>(id.Data4[0]), static_cast<unsigned int>(id.Data4[1]),
 			static_cast<unsigned int>(id.Data4[2]), static_cast<unsigned int>(id.Data4[3]), static_cast<unsigned int>(id.Data4[4]), static_cast<unsigned int>(id.Data4[5]), static_cast<unsigned int>(id.Data4[6]), static_cast<unsigned int>(id.Data4[7]));
 #else
-		snprintf(str, uuid_str_max, "{%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
+		::snprintf(str, uuid_str_max, "{%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
 			*reinterpret_cast<const uint32_t*>(&id[0]),
 			static_cast<unsigned int>(*reinterpret_cast<const uint16_t*>(&id[4])),
 			static_cast<unsigned int>(*reinterpret_cast<const uint16_t*>(&id[6])),