Remove redundant string initialisation

Both std::string and dstringt are default-initialised to an empty string.

Author: tautschnig

jbmc/src/java_bytecode/expr2java.cpp

@@ -276,7 +276,7 @@ std::string expr2javat::convert_rec(
     // so we make one up, loosely inspired by the syntax
     // of lambda expressions.
 
-    std::string dest="";
+    std::string dest;
 
     dest+='(';
     const java_method_typet::parameterst &parameters = method_type.parameters();

src/analyses/local_may_alias.cpp

@@ -458,7 +458,7 @@ void local_may_aliast::output(
           if(loc_info.aliases.find(j)==i)
           {
             assert(j<objects.size());
-            irep_idt identifier = "";
+            irep_idt identifier;
             if(objects[j].id() == ID_symbol)
               identifier = to_symbol_expr(objects[j]).get_identifier();
             out << ' ' << from_expr(ns, identifier, objects[j]);

src/cpp/cpp_typecheck_resolve.cpp

@@ -879,7 +879,7 @@ cpp_scopet &cpp_typecheck_resolvet::resolve_scope(
     recursive=false;
   }
 
-  std::string final_base_name="";
+  std::string final_base_name;
   template_args.make_nil();
 
   while(pos!=cpp_name.get_sub().end())

src/goto-analyzer/show_on_source.cpp

@@ -58,7 +58,7 @@ static void print_with_indent(
 {
   const std::size_t p = indent_line.find_first_not_of(" \t");
   const std::string indent =
-    p == std::string::npos ? std::string("") : std::string(indent_line, 0, p);
+    p == std::string::npos ? std::string() : std::string(indent_line, 0, p);
   std::istringstream in(src);
   std::string src_line;
   while(std::getline(in, src_line))

src/goto-instrument/dot.cpp

@@ -104,7 +104,7 @@ void dott::write_dot_subgraph(
       if(it==instructions.end() ||
          seen.find(it)!=seen.end()) continue;
 
-      std::stringstream tmp("");
+      std::stringstream tmp;
       if(it->is_goto())
       {
         if(it->guard.is_true())

src/goto-instrument/dump_c_class.h

@@ -71,7 +71,6 @@ class dump_ct
 
     explicit typedef_infot(const irep_idt &name):
       typedef_name(name),
-      type_decl_str(""),
       early(false)
     {
     }

src/goto-instrument/goto_program2code.cpp

@@ -1863,7 +1863,7 @@ void goto_program2codet::cleanup_expr(exprt &expr, bool no_typecast)
       // Replace by a function call to nondet_...
       // We first search for a suitable one in the symbol table.
 
-      irep_idt id="";
+      irep_idt id;
 
       for(symbol_tablet::symbolst::const_iterator
           it=symbol_table.symbols.begin();
@@ -1887,7 +1887,7 @@ void goto_program2codet::cleanup_expr(exprt &expr, bool no_typecast)
 
       if(id.empty())
       {
-        irep_idt base_name="";
+        irep_idt base_name;
 
         if(expr.type().get(ID_C_c_type)!="")
         {

src/goto-programs/string_abstraction.cpp

@@ -942,7 +942,7 @@ bool string_abstractiont::build_symbol(const symbol_exprt &sym, exprt &dest)
   const typet &abstract_type=build_abstraction_type(symbol.type);
   CHECK_RETURN(!abstract_type.is_nil());
 
-  irep_idt identifier="";
+  irep_idt identifier;
 
   if(current_args.find(symbol.name)!=current_args.end())
     identifier=id2string(symbol.name)+arg_suffix;

src/solvers/qbf/qbf_qube.cpp

@@ -55,7 +55,7 @@ propt::resultt qbf_qubet::prop_solve()
     write_qdimacs_cnf(out);
   }
 
-  std::string options="";
+  std::string options;
 
   // solve it
   int res=system(

src/solvers/qbf/qbf_qube_core.cpp

@@ -51,7 +51,7 @@ propt::resultt qbf_qube_coret::prop_solve()
     write_qdimacs_cnf(out);
   }
 
-  std::string options="";
+  std::string options;
 
   // solve it
   int res=system((