fix a real error (m68kdasm) and some harmless performance warnings and use modern headers

Src/CPU/68K/Musashi/m68kdasm.c

@@ -251,8 +251,8 @@ static const char* g_cpcc[64] =
 {/* 000    001    010    011    100    101    110    111 */
 	  "f",  "eq", "ogt", "oge", "olt", "ole", "ogl",  "or", /* 000 */
 	 "un", "ueq", "ugt", "uge", "ult", "ule",  "ne",   "t", /* 001 */
-	 "sf", "seq",  "gt",  "ge",  "lt",  "le",  "gl"  "gle", /* 010 */
+	 "sf", "seq",  "gt",  "ge",  "lt",  "le",  "gl", "gle", /* 010 */
-  "ngle", "ngl", "nle", "nlt", "nge", "ngt", "sne",  "st", /* 011 */
+	 "ngle", "ngl", "nle", "nlt", "nge", "ngt", "sne","st", /* 011 */
 	  "?",   "?",   "?",   "?",   "?",   "?",   "?",   "?", /* 100 */
 	  "?",   "?",   "?",   "?",   "?",   "?",   "?",   "?", /* 101 */
 	  "?",   "?",   "?",   "?",   "?",   "?",   "?",   "?", /* 110 */

Src/GameLoader.cpp

@@ -20,7 +20,7 @@ bool GameLoader::LoadZipArchive(ZipArchive *zip, const std::string &zipfilename)
   zip->zfs.push_back(zf);
 
   // Identify all files in zip archive
-  int err = UNZ_OK;
+  int err;
   for (err = unzGoToFirstFile(zf); err == UNZ_OK; err = unzGoToNextFile(zf))
   {
     unz_file_info file_info;
@@ -193,11 +193,11 @@ static void PopulateGameInfo(Game *game, const Util::Config::Node &game_node)
   game->name = game_node["name"].ValueAs<std::string>();
   game->parent = game_node["parent"].ValueAsDefault<std::string>(std::string());
   game->title = game_node["identity/title"].ValueAsDefault<std::string>("Unknown");
-  game->version = game_node["identity/version"].ValueAsDefault<std::string>("");
+  game->version = game_node["identity/version"].ValueAsDefault<std::string>(std::string());
   game->manufacturer = game_node["identity/manufacturer"].ValueAsDefault<std::string>("Unknown");
   game->year = game_node["identity/year"].ValueAsDefault<unsigned>(0);
-  game->stepping = game_node["hardware/stepping"].ValueAsDefault<std::string>("");
+  game->stepping = game_node["hardware/stepping"].ValueAsDefault<std::string>(std::string());
-  game->mpeg_board = game_node["hardware/mpeg_board"].ValueAsDefault<std::string>("");
+  game->mpeg_board = game_node["hardware/mpeg_board"].ValueAsDefault<std::string>(std::string());
   std::map<std::string, Game::AudioTypes> audio_types
   {
     { "",                      Game::STEREO_LR }, // default to stereo
@@ -212,7 +212,7 @@ static void PopulateGameInfo(Game *game, const Util::Config::Node &game_node)
   };
   std::string audio_type = game_node["hardware/audio"].ValueAsDefault<std::string>(std::string());
   game->audio = audio_types[audio_type];
-  game->pci_bridge = game_node["hardware/pci_bridge"].ValueAsDefault<std::string>("");
+  game->pci_bridge = game_node["hardware/pci_bridge"].ValueAsDefault<std::string>(std::string());
   game->real3d_pci_id = game_node["hardware/real3d_pci_id"].ValueAsDefault<uint32_t>(0);
   game->real3d_status_bit_set_percent_of_frame = game_node["hardware/real3d_status_bit_set_percent_of_frame"].ValueAsDefault<float>(0);
   game->encryption_key = game_node["hardware/encryption_key"].ValueAsDefault<uint32_t>(0);
@@ -849,7 +849,7 @@ std::string StripFilename(const std::string &filepath)
 
   // If none found, there is directory component here
   if (last_slash == std::string::npos)
-    return "";
+    return std::string();
 
   // Otherwise, strip everything after the slash
   return std::string(filepath, 0, last_slash + 1);

Src/Graphics/New3D/GLSLShader.cpp

@@ -1,5 +1,5 @@
 #include "GLSLShader.h"
-#include <stdio.h>
+#include <cstdio>
 
 GLSLShader::GLSLShader() {
 
@@ -107,6 +107,3 @@ int GLSLShader::GetAttributeLocation(const char *str)
 {
 	return glGetAttribLocation(m_program, str);
 }
-
-
-

Src/Graphics/New3D/Model.h

@@ -3,9 +3,8 @@
 
 #include <vector>
 #include <unordered_map>
-#include <map>
 #include <memory>
-#include <string.h>
+#include <cstring>
 #include "Texture.h"
 #include "Mat4.h"
 
@@ -32,24 +31,19 @@ struct Vertex					// half vertex
 
 	static bool Equal(const Vertex& p1, const Vertex& p2)
 	{
-		if (p1.pos[0] == p2.pos[0] &&
+		return (p1.pos[0] == p2.pos[0] &&
 			p1.pos[1] == p2.pos[1] &&
-			p1.pos[2] == p2.pos[2])
+			p1.pos[2] == p2.pos[2]);
-		{
-			return true;
-		}
-
-		return false;
 	}
 
 	static void Average(const Vertex& p1, const Vertex& p2, Vertex& p3)
 	{
 		p3.pos[3] = 1.0f;	//always 1
-		p3.fixedShade = (p1.fixedShade + p2.fixedShade) / 2.0f;
+		p3.fixedShade = (p1.fixedShade + p2.fixedShade) * 0.5f;
 
-		for (int i = 0; i < 3; i++)	{ p3.pos[i] = (p1.pos[i] + p2.pos[i]) / 2.0f; }
+		for (int i = 0; i < 3; i++)	{ p3.pos[i] = (p1.pos[i] + p2.pos[i]) * 0.5f; }
-		for (int i = 0; i < 3; i++)	{ p3.normal[i] = (p1.normal[i] + p2.normal[i]) / 2.0f; }
+		for (int i = 0; i < 3; i++)	{ p3.normal[i] = (p1.normal[i] + p2.normal[i]) * 0.5f; }
-		for (int i = 0; i < 2; i++)	{ p3.texcoords[i] = (p1.texcoords[i] + p2.texcoords[i]) / 2.0f; }
+		for (int i = 0; i < 2; i++)	{ p3.texcoords[i] = (p1.texcoords[i] + p2.texcoords[i]) * 0.5f; }
 	}
 };
 

Src/Graphics/New3D/PolyHeader.cpp

@@ -117,7 +117,7 @@ int	PolyHeader::NumVerts()
 
 int PolyHeader::NumSharedVerts()
 {
-	int sharedVerts[] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
+	static const int sharedVerts[] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
 
 	return sharedVerts[header[0] & 0xf];
 }
@@ -135,9 +135,9 @@ bool PolyHeader::SharedVertex(int vertex)
 
 void PolyHeader::FaceNormal(float n[3]) 
 {
-	n[0] = (float)(((INT32)header[1]) >> 8) * (1.0f / 4194304.0f);
+	n[0] = (float)(((INT32)header[1]) >> 8) * (float)(1.0 / 4194304.0);
-	n[1] = (float)(((INT32)header[2]) >> 8) * (1.0f / 4194304.0f);
+	n[1] = (float)(((INT32)header[2]) >> 8) * (float)(1.0 / 4194304.0);
-	n[2] = (float)(((INT32)header[3]) >> 8) * (1.0f / 4194304.0f);
+	n[2] = (float)(((INT32)header[3]) >> 8) * (float)(1.0 / 4194304.0);
 }
 
 float PolyHeader::UVScale()

Src/Graphics/New3D/R3DScrollFog.cpp

@@ -43,7 +43,7 @@ void main()
 	position = spotEllipse.xy;
 	size = spotEllipse.zw;
 	ellipse = length((gl_FragCoord.xy - position) / size);
-	ellipse = pow(ellipse, 2.0);			// decay rate = square of distance from center
+	ellipse = ellipse * ellipse;			// decay rate = square of distance from center
 	ellipse = 1.0 - ellipse;				// invert
 	ellipse = max(0.0, ellipse);			// clamp
 

Src/Graphics/New3D/R3DShader.cpp

@@ -134,6 +134,7 @@ GLint R3DShader::GetVertexAttribPos(const std::string& attrib)
 	if (m_vertexLocCache.count(attrib)==0) {
 		auto pos = glGetAttribLocation(m_shaderProgram, attrib.c_str());
 		m_vertexLocCache[attrib] = pos;
+		return pos;
 	}
 
 	return m_vertexLocCache[attrib];

Src/Graphics/New3D/R3DShader.h

@@ -4,7 +4,7 @@
 #include <GL/glew.h>
 #include "Util/NewConfig.h"
 #include "Model.h"
-#include <map>
+#include <unordered_map>
 #include <string>
 
 namespace New3D {
@@ -109,7 +109,7 @@ private:
 	GLint m_locDiscardAlpha;
 
 	// vertex attribute position cache
-	std::map<std::string, GLint> m_vertexLocCache;
+	std::unordered_map<std::string, GLint> m_vertexLocCache;
 
 };
 

Src/Graphics/New3D/TextureSheet.cpp

@@ -4,7 +4,7 @@ namespace New3D {
 
 TextureSheet::TextureSheet()
 {
-	m_temp.resize(1024 * 1024 * 4);	// temporay buffer for textures
+	m_temp.resize(1024 * 1024 * 4);	// temporary buffer for textures
 }
 
 int TextureSheet::ToIndex(int x, int y)

Src/Graphics/New3D/Vec.cpp

@@ -1,33 +1,9 @@
 #include "Vec.h"
 #include <cmath>
+#include <algorithm>
 
 namespace New3D {
 
-static float fastSqrt(float number) {
-    long i;
-    float x, y;
-    const float f = 1.5F;
-
-    x = number * 0.5F;
-    y  = number;
-    i  = * ( long * ) &y;
-    i  = 0x5f375a86 - ( i >> 1 );
-    y  = * ( float * ) &i;
-    y  = y * ( f - ( x * y * y ) );
-    y  = y * ( f - ( x * y * y ) );
-    return number * y;
-}
-
-static float fastInvSqrt(float x)
-{
-	float xhalf = 0.5f*x;
-	int i = *(int*)&x;			// get bits for floating value
-	i = 0x5f375a86- (i>>1);		// gives initial guess y0
-	x = *(float*)&i;			// convert bits back to float
-	x = x*(1.5f-xhalf*x*x);		// Newton step, repeating increases accuracy
-	return x;
-}
-
 void V3::subtract(const Vec3 a, const Vec3 b, Vec3 out) {
 
 	out[0] = a[0] - b[0];
@@ -58,7 +34,7 @@ void V3::add(Vec3 a, const Vec3 b) {
 
 void V3::divide(Vec3 a, float number) {
 
-	multiply(a,1/number);
+	multiply(a,1.f/number);
 }
 
 void V3::multiply(Vec3 a, float number) {
@@ -123,13 +99,13 @@ float V3::length(const Vec3 v) {
 void V3::normalise(Vec3 v) {
 
 	//========
-	float len;
+	float inv_len;
 	//========
 
-	len = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
+	inv_len = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
-	len = fastInvSqrt(len);
+	inv_len = 1.f/std::sqrt(inv_len);
 
-	multiply(v,len);
+	multiply(v,inv_len);
 }
 
 void V3::multiplyAdd(const Vec3 a, float scale, const Vec3 b, Vec3 out) {
@@ -141,9 +117,9 @@ void V3::multiplyAdd(const Vec3 a, float scale, const Vec3 b, Vec3 out) {
 
 void V3::reset(Vec3 v) {
 
-	v[0] = 0;
+	v[0] = 0.f;
-	v[1] = 0;
+	v[1] = 0.f;
-	v[2] = 0;
+	v[2] = 0.f;
 }
 
 void V3::set(Vec3 v, float value) {
@@ -171,7 +147,7 @@ void V3::reflect(const Vec3 a, const Vec3 b, Vec3 out) {
 
 	V3::copy(a,v);
 
-	temp = V3::dotProduct(a,b) * 2;
+	temp = V3::dotProduct(a,b) * 2.f;
 
 	V3::multiply(v,temp);
 	V3::subtract(b,v,out);
@@ -191,16 +167,16 @@ void V3::createNormal(const Vec3 a, const Vec3 b, const Vec3 c, Vec3 outNormal)
 
 void V3::_max(Vec3 a, const Vec3 compare) {
 
-	if(a[0] < compare[0]) a[0] = compare[0];
+	a[0] = std::max(compare[0], a[0]);
-	if(a[1] < compare[1]) a[1] = compare[1];
+	a[1] = std::max(compare[1], a[1]);
-	if(a[2] < compare[2]) a[2] = compare[2];
+	a[2] = std::max(compare[2], a[2]);
 }
 
 void V3::_min(Vec3 a, const Vec3 compare) {
 
-	if(a[0] > compare[0]) a[0] = compare[0];
+	a[0] = std::min(compare[0], a[0]);
-	if(a[1] > compare[1]) a[1] = compare[1];
+	a[1] = std::min(compare[1], a[1]);
-	if(a[2] > compare[2]) a[2] = compare[2];
+	a[2] = std::min(compare[2], a[2]);
 }
 
 bool V3::cmp(const Vec3 a, float b) {
@@ -223,14 +199,9 @@ bool V3::cmp(const Vec3 a, const Vec3 b) {
 
 void V3::clamp(Vec3 a, float _min, float _max) {
 	
-	if(a[0] < _min) a[0] = _min;
+	a[0] = std::min(std::max(_min, a[0]), _max);
-	if(a[0] > _max) a[0] = _max;
+	a[1] = std::min(std::max(_min, a[1]), _max);
-
+	a[2] = std::min(std::max(_min, a[2]), _max);
-	if(a[1] < _min) a[1] = _min;
-	if(a[1] > _max) a[1] = _max;
-
-	if(a[2] < _min) a[2] = _min;
-	if(a[2] > _max) a[2] = _max;
 }
 
 } // New3D

Src/Inputs/InputSystem.cpp

@@ -724,7 +724,7 @@ void CInputSystem::CheckKeySources(int kbdNum, bool fullAxisOnly, vector<CInputS
       find(badSources.begin(), badSources.end(), source) == badSources.end())
     {
       // Update mapping string and add source to list
-      if (sources.size() == 0)
+      if (sources.empty())
         mapping.assign("KEY");
       else
         mapping.append("+KEY");
@@ -758,7 +758,7 @@ void CInputSystem::CheckMouseSources(int mseNum, bool fullAxisOnly, bool mseCent
     {
       // Otherwise, update mapping string and add source to list
       const char *partName = LookupName(msePart);
-      if (sources.size() == 0)
+      if (sources.empty())
         mapping.assign("MOUSE");
       else
         mapping.append("+MOUSE");
@@ -787,7 +787,7 @@ void CInputSystem::CheckJoySources(int joyNum, bool fullAxisOnly, vector<CInputS
     {
       // Otherwise, update mapping string and add source to list
       const char *partName = LookupName(joyPart);
-      if (sources.size() == 0)
+      if (sources.empty())
         mapping.assign("JOY");
       else
         mapping.append("+JOY");
@@ -800,7 +800,7 @@ void CInputSystem::CheckJoySources(int joyNum, bool fullAxisOnly, vector<CInputS
   }
 }
 
-bool CInputSystem::ParseInt(string str, int &num)
+bool CInputSystem::ParseInt(const string& str, int &num)
 {
   stringstream ss(str);
   return !(ss >> num).fail();
@@ -813,7 +813,7 @@ string CInputSystem::IntToString(int num)
   return ss.str();
 }
 
-bool CInputSystem::EqualsIgnoreCase(string str1, const char *str2)
+bool CInputSystem::EqualsIgnoreCase(const string& str1, const char *str2)
 {
   for (string::const_iterator ci = str1.begin(); ci < str1.end(); ++ci) 
   {
@@ -824,7 +824,7 @@ bool CInputSystem::EqualsIgnoreCase(string str1, const char *str2)
   return *str2 == '\0';
 }
 
-bool CInputSystem::StartsWithIgnoreCase(string str1, const char *str2)
+bool CInputSystem::StartsWithIgnoreCase(const string& str1, const char *str2)
 {
   for (string::const_iterator ci = str1.begin(); ci < str1.end(); ++ci) 
   {
@@ -1023,7 +1023,7 @@ CInputSource *CInputSystem::ParseSingleSource(string str)
           if (rightSource != NULL)
             sources.push_back(rightSource);
         }
-        if (sources.size() > 0)
+        if (!sources.empty())
           return new CMultiInputSource(true, sources);
       }
       return m_emptySource;
@@ -1772,7 +1772,7 @@ bool CInputSystem::ReadMapping(char *buffer, unsigned bufSize, bool fullAxisOnly
     CheckAllSources(readFlags, fullAxisOnly, mseCentered, sources, mapping, badSources);
 
     // When some inputs have been activated, keep looping until they have all been released again.
-    if (sources.size() > 0)
+    if (!sources.empty())
     {
       // Check each source is no longer active
       bool active = false;

Src/Inputs/InputSystem.h

@@ -420,13 +420,13 @@ private:
    */
   void CheckJoySources(int joyNum, bool fullAxisOnly, std::vector<CInputSource*> &sources, std::string &mapping, std::vector<CInputSource*> &badSources);
 
-  bool ParseInt(std::string str, int &num);
+  bool ParseInt(const std::string& str, int &num);
 
   std::string IntToString(int num);
 
-  bool EqualsIgnoreCase(std::string str1, const char *str2);
+  bool EqualsIgnoreCase(const std::string& str1, const char *str2);
 
-  bool StartsWithIgnoreCase(std::string str1, const char *str2);
+  bool StartsWithIgnoreCase(const std::string& str1, const char *str2);
 
   /*
    * Returns true if the given string represents a valid key name.

Src/Inputs/MultiInputSource.cpp

@@ -36,7 +36,7 @@ using namespace std;
 ESourceType CMultiInputSource::GetCombinedType(vector<CInputSource*> &sources)
 {
 	// Check if vector is empty
-	if (sources.size() == 0)
+	if (sources.empty())
 		return SourceEmpty;
 	// Otherwise, see whether all sources are switches, or if have a full- or half-axis present
 	bool allSwitches = true;

Src/Model3/53C810Disasm.cpp

@@ -29,10 +29,10 @@
  * be decoded incorrectly.
  */
 
-#include <stdio.h>
+#include <cstdio>
-#include <string.h>
+#include <cstring>
 #ifdef STANDALONE
-#include <stdlib.h>
+#include <cstdlib>
 #endif
 #include "Types.h"
 

Src/Model3/93C46.cpp

@@ -33,7 +33,7 @@
 
 #include "93C46.h"
 
-#include <string.h>
+#include <cstring>
 #include "Supermodel.h"
 
 

Src/Model3/DSB.cpp

@@ -143,7 +143,7 @@ int CDSBResampler::UpSampleAndMix(INT16 *outL, INT16 *outR, INT16 *inL, INT16 *i
 	int		outIdx = 0;
 	int		inIdx = 0;
 	INT32	leftSample, rightSample, leftSoundSample, rightSoundSample;
-	INT32	v[2], musicVol, soundVol;
+	INT32	v[2], musicVol;
 
 	// Obtain program volume settings and convert to 24.8 fixed point (0-200 -> 0x00-0x200)
 	musicVol = m_config["MusicVolume"].ValueAs<int>();

Src/Model3/Model3.cpp

@@ -1144,7 +1144,7 @@ UINT16 CModel3::Read16(UINT32 addr)
 
 #ifdef NET_BOARD
   case 0xc0: // spikeout call this
-  // interresting : poking @4 master to same value as slave (0x100) or simply !=0 -> connected and go in game, but freeze (prints comm error) as soon as players appear after the gate
+  // interesting : poking @4 master to same value as slave (0x100) or simply !=0 -> connected and go in game, but freeze (prints comm error) as soon as players appear after the gate
   // sort of sync ack ? who writes this 16b value ?
   {
     UINT16 result;

Src/Model3/Real3D.cpp

@@ -809,7 +809,7 @@ uint32_t CReal3D::ReadRegister(unsigned reg)
 	int index = (reg - 20) / 4;
 	float val = Render3D->GetLosValue(index);
 
-	if (val) {
+	if (val != 0.f) {
 		//val = 1.0f / val;		// test program indicate z values are 1 over
 		return 0xffffffff;		// infinity
 	}
@@ -922,7 +922,6 @@ uint32_t CReal3D::GetASICIDCode(ASIC asic) const
 }
 
 void CReal3D::SetStepping(int stepping, uint32_t pciIDValue)
-
 {
   step = stepping;
   if ((step!=0x10) && (step!=0x15) && (step!=0x20) && (step!=0x21))

Src/Model3/Real3D.h

@@ -36,7 +36,7 @@
 #include "Util/NewConfig.h"
 
 #include <cstdint>
-#include <map>
+#include <unordered_map>
 
 /* 
  * QueuedUploadTextures:
@@ -505,7 +505,7 @@ private:
   bool m_evenFrame = false;
   
   // Internal ASIC state
-  std::map<ASIC, uint32_t> m_asicID;
+  std::unordered_map<ASIC, uint32_t> m_asicID;
   uint64_t m_internalRenderConfig[2];
 };
 

Src/Network/NetBoard.h

@@ -104,7 +104,7 @@ private:
 	// netsock
 	UINT16 port_in = 0;
 	UINT16 port_out = 0;
-	std::string addr_out = "";
+	std::string addr_out;
 
 	std::unique_ptr<TCPSend> nets;
 	std::unique_ptr<TCPReceive> netr;

Src/Network/SimNetBoard.h

@@ -85,7 +85,7 @@ private:
 	// netsock
 	uint16_t port_in = 0;
 	uint16_t port_out = 0;
-	std::string addr_out = "";
+	std::string addr_out;
 	std::thread m_connectThread;
 	std::atomic_bool m_quit = false;
 	std::atomic_bool m_connected = false;

Src/Network/TCPSend.cpp

@@ -60,7 +60,7 @@ bool TCPSend::Send(const void * data, int length)
 
 	DPRINTF("Sending %i bytes\n", length);
 
-	int sent = 0;
+	int sent;
 
 	sent = SDLNet_TCP_Send(m_socket, &length, sizeof(int));		// pack the length at the start of transmission.
 

Src/OSD/Logger.cpp

@@ -112,7 +112,7 @@ std::shared_ptr<CLogger> CreateLogger(const Util::Config::Node &config)
   loggers.push_back(std::make_shared<CConsoleErrorLogger>());
 
   // Parse other log outputs
-  std::string logOutputs = config["LogOutput"].ValueAsDefault<std::string>("");
+  std::string logOutputs = config["LogOutput"].ValueAsDefault<std::string>(std::string());
   std::vector<std::string> outputs = Util::Format(logOutputs).Split(',');
 
   std::set<std::string> supportedDestinations { "stdout", "stderr", "syslog" };

Src/OSD/Windows/DirectInputSystem.cpp

@@ -1444,7 +1444,7 @@ HRESULT CDirectInputSystem::CreateJoystickEffect(LPDIRECTINPUTDEVICE8 joystick,
 	DICONSTANTFORCE dicf;
 	DICONDITION dic;
 	DIPERIODIC dip;
-	DIENVELOPE die;
+	//DIENVELOPE die;
 	GUID guid;
 
 	// Set common effects parameters
@@ -1883,7 +1883,7 @@ bool CDirectInputSystem::ProcessForceFeedbackCmd(int joyNum, int axisNum, ForceF
 		DICONSTANTFORCE dicf;
 		DICONDITION dic;
 		DIPERIODIC dip;
-		DIENVELOPE die;
+		//DIENVELOPE die;
 
 		// Set common parameters
 		DIEFFECT eff;

Src/Util/BitRegister.cpp

@@ -276,7 +276,7 @@ namespace Util
   std::string BitRegister::ToBinaryString() const
   {
     if (Empty())
-      return std::string("");
+      return std::string();
     std::string out(Size(), '0');
     for (size_t i = 0; i < Size(); i++)
     {
@@ -287,9 +287,9 @@ namespace Util
   
   std::string BitRegister::ToHexString() const
   {
-    const char digits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
+    static const char digits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
     if (Empty())
-      return std::string("");
+      return std::string();
     size_t partial = Size() & 3;
     size_t num_digits = Size() / 4 + (partial != 0 ? 1 : 0);
     std::string out(num_digits + 2, '0');