Fix Error.cpp compile for Windows

library/Error.cpp

@@ -3,33 +3,33 @@
 
 using namespace DFHack::Error;
 
-inline const char *safe_str(const char *s)
+inline std::string safe_str(const char *s)
 {
     return s ? s : "(NULL)";
 }
 
 NullPointer::NullPointer(const char *varname)
-    :All(stl_concat("NULL pointer: ", safe_str(varname))),
+    :All("NULL pointer: " + safe_str(varname)),
     varname(varname)
 {}
 
 InvalidArgument::InvalidArgument(const char *expr)
-    :All(stl_concat("Invalid argument; expected: ", safe_str(expr))),
+    :All("Invalid argument; expected: " + safe_str(expr)),
     expr(expr)
 {}
 
 VTableMissing::VTableMissing(const char *name)
-    :All(stl_concat("Missing vtable address: ", safe_str(name))),
+    :All("Missing vtable address: " + safe_str(name)),
     name(name)
 {}
 
 SymbolsXmlParse::SymbolsXmlParse(const char* desc, int id, int row, int col)
-    :AllSymbols(stl_concat("error ", id, ": ", desc, ", at row ", row, " col ", col)),
+    :AllSymbols(stl_sprintf("error %d: %s, at row %d col %d", id, desc, row, col)),
     desc(safe_str(desc)), id(id), row(row), col(col)
 {}
 
 SymbolsXmlBadAttribute::SymbolsXmlBadAttribute(const char *attr)
-    :AllSymbols(stl_concat("attribute is either missing or invalid: ", safe_str(attr))),
+    :AllSymbols("attribute is either missing or invalid: " + safe_str(attr)),
     attr(safe_str(attr))
 {}
 
@@ -38,7 +38,6 @@ SymbolsXmlNoRoot::SymbolsXmlNoRoot()
 {}
 
 SymbolsXmlUnderspecifiedEntry::SymbolsXmlUnderspecifiedEntry(const char *where)
-    :AllSymbols(stl_concat("Underspecified symbol file entry, each entry needs to set both the name attribute and have a value. parent: ",
+    :AllSymbols("Underspecified symbol file entry, each entry needs to set both the name attribute and have a value. parent: " + safe_str(where)),
-        safe_str(where))),
     where(safe_str(where))
 {}

library/include/MiscUtils.h

@@ -349,24 +349,6 @@ DFHACK_EXPORT uint64_t GetTimeMs64();
 DFHACK_EXPORT std::string stl_sprintf(const char *fmt, ...);
 DFHACK_EXPORT std::string stl_vsprintf(const char *fmt, va_list args);
 
-// https://stackoverflow.com/questions/27375089/what-is-the-easiest-way-to-print-a-variadic-parameter-pack-using-stdostream
-template<typename... Args>
-inline std::string stl_concat(Args... args)
-{
-    std::ostringstream os;
-    (void)(int[]){0, (void(os << std::forward<Args>(args)), 0)...};
-    return os.str();
-}
-
-template<typename... Args>
-inline std::string stl_concat(const std::string &sep, Args... args)
-{
-    std::ostringstream os;
-    (void)(int[]){0, (void(os << sep << std::forward<Args>(args)), 0)...};
-    return os.str();
-}
-
-
 // Conversion between CP437 and UTF-8
 DFHACK_EXPORT std::string UTF2DF(const std::string &in);
 DFHACK_EXPORT std::string DF2UTF(const std::string &in);