remove a few string copies

src/api/api_ast.cpp

@@ -146,8 +146,7 @@ extern "C" {
         ast_manager& m = mk_c(c)->m();
         recfun::decl::plugin& p = mk_c(c)->recfun().get_plugin();
         if (!p.has_def(d)) {
-            std::string msg = "function " + mk_pp(d, m) + " needs to be declared using rec_func_decl";
+            SET_ERROR_CODE(Z3_INVALID_ARG, "function " + mk_pp(d, m) + " needs to be declared using rec_func_decl");
-            SET_ERROR_CODE(Z3_INVALID_ARG, msg.c_str());
             return;
         }
         expr_ref abs_body(m);
@@ -168,8 +167,7 @@ extern "C" {
             return;
         }
         if (!pd.get_def()->get_cases().empty()) {
-            std::string msg = "function " + mk_pp(d, m) + " has already been given a definition";
+            SET_ERROR_CODE(Z3_INVALID_ARG, "function " + mk_pp(d, m) + " has already been given a definition");
-            SET_ERROR_CODE(Z3_INVALID_ARG, msg.c_str());
             return;            
         }
                 

src/api/api_ast_map.cpp

@@ -160,8 +160,8 @@ extern "C" {
         for (; it != end; ++it) {
             buffer << "\n  (" << mk_ismt2_pp(it->m_key, mng, 3) << "\n   " << mk_ismt2_pp(it->m_value, mng, 3) << ")";
         }
-        buffer << ")";
+        buffer << ')';
-        return mk_c(c)->mk_external_string(buffer.str());
+        return mk_c(c)->mk_external_string(std::move(buffer).str());
         Z3_CATCH_RETURN(nullptr);
     }
 

src/api/api_context.cpp

@@ -338,12 +338,12 @@ namespace api {
                 std::ostringstream buffer;
                 app * a = to_app(n);
                 buffer << mk_pp(a->get_decl(), m()) << " applied to: ";
-                if (a->get_num_args() > 1) buffer << "\n";
+                if (a->get_num_args() > 1) buffer << '\n';
                 for (unsigned i = 0; i < a->get_num_args(); ++i) {
                     buffer << mk_bounded_pp(a->get_arg(i), m(), 3) << " of sort ";
-                    buffer << mk_pp(a->get_arg(i)->get_sort(), m()) << "\n";
+                    buffer << mk_pp(a->get_arg(i)->get_sort(), m()) << '\n';
                 }
-                auto str = buffer.str();
+                auto str = std::move(buffer).str();
                 warning_msg("%s", str.c_str());
                 break;
             }

src/api/api_fpa.cpp

@@ -1022,7 +1022,7 @@ extern "C" {
         if (mpfm.is_inf(val)) mpqm.set(q, 0);
         std::stringstream ss;
         mpqm.display_decimal(ss, q, sbits);
-        return mk_c(c)->mk_external_string(ss.str());
+        return mk_c(c)->mk_external_string(std::move(ss).str());
         Z3_CATCH_RETURN("");
     }
 
@@ -1100,7 +1100,7 @@ extern "C" {
         }
         std::stringstream ss;
         ss << exp;
-        return mk_c(c)->mk_external_string(ss.str());
+        return mk_c(c)->mk_external_string(std::move(ss).str());
         Z3_CATCH_RETURN("");
     }
 

src/api/api_goal.cpp

@@ -185,7 +185,7 @@ extern "C" {
         std::ostringstream buffer;
         to_goal_ref(g)->display(buffer);
         // Hack for removing the trailing '\n'
-        std::string result = buffer.str();
+        std::string result = std::move(buffer).str();
         SASSERT(result.size() > 0);
         result.resize(result.size()-1);
         return mk_c(c)->mk_external_string(std::move(result));
@@ -203,7 +203,7 @@ extern "C" {
         }
         to_goal_ref(g)->display_dimacs(buffer, include_names);
         // Hack for removing the trailing '\n'
-        std::string result = buffer.str();
+        std::string result = std::move(buffer).str();
         SASSERT(result.size() > 0);
         result.resize(result.size()-1);
         return mk_c(c)->mk_external_string(std::move(result));

src/api/api_model.cpp

@@ -432,14 +432,14 @@ extern "C" {
         if (mk_c(c)->get_print_mode() == Z3_PRINT_SMTLIB2_COMPLIANT) {
             model_smt2_pp(buffer, mk_c(c)->m(), *(to_model_ref(m)), 0);
             // Hack for removing the trailing '\n'
-            result = buffer.str();
+            result = std::move(buffer).str();
             if (!result.empty())
                 result.resize(result.size()-1);
         }
         else {
             model_params p;
             model_v2_pp(buffer, *(to_model_ref(m)), p.partial());
-            result = buffer.str();
+            result = std::move(buffer).str();
         }
         return mk_c(c)->mk_external_string(std::move(result));
         Z3_CATCH_RETURN(nullptr);

src/api/api_numeral.cpp

@@ -189,7 +189,7 @@ extern "C" {
         if (ok && r.is_int() && !r.is_neg()) {
             std::stringstream strm;
             r.display_bin(strm, r.get_num_bits());
-            return mk_c(c)->mk_external_string(strm.str());
+            return mk_c(c)->mk_external_string(std::move(strm).str());
         }
         else {
             SET_ERROR_CODE(Z3_INVALID_ARG, nullptr);
@@ -237,7 +237,7 @@ extern "C" {
             else if (mk_c(c)->fpautil().is_numeral(to_expr(a), tmp)) {
                 std::ostringstream buffer;
                 fu.fm().display_smt2(buffer, tmp, false);
-                return mk_c(c)->mk_external_string(buffer.str());
+                return mk_c(c)->mk_external_string(std::move(buffer).str());
             }
             else {
                 SET_ERROR_CODE(Z3_INVALID_ARG, nullptr);
@@ -288,21 +288,21 @@ extern "C" {
         if (u.is_numeral(e, r) && !r.is_int()) {
             std::ostringstream buffer;
             r.display_decimal(buffer, precision);
-            return mk_c(c)->mk_external_string(buffer.str());
+            return mk_c(c)->mk_external_string(std::move(buffer).str());
         }
         if (u.is_irrational_algebraic_numeral(e)) {
             algebraic_numbers::anum const & n = u.to_irrational_algebraic_numeral(e);
             algebraic_numbers::manager & am   = u.am();
             std::ostringstream buffer;
             am.display_decimal(buffer, n, precision);
-            return mk_c(c)->mk_external_string(buffer.str());
+            return mk_c(c)->mk_external_string(std::move(buffer).str());
         }
         else if (mk_c(c)->fpautil().is_rm_numeral(to_expr(a), rm))
             return Z3_get_numeral_string(c, a);
         else if (mk_c(c)->fpautil().is_numeral(to_expr(a), ftmp)) {
             std::ostringstream buffer;
             fu.fm().display_decimal(buffer, ftmp, 12);
-            return mk_c(c)->mk_external_string(buffer.str());
+            return mk_c(c)->mk_external_string(std::move(buffer).str());
         }
         else if (Z3_get_numeral_rational(c, a, r)) {
             return mk_c(c)->mk_external_string(r.to_string());

src/api/api_solver.cpp

@@ -170,8 +170,8 @@ extern "C" {
             if (g_is_threaded || g_thread_id != std::this_thread::get_id()) {
                 g_is_threaded = true;
                 std::ostringstream strm;
-                strm << smt2log << "-" << std::this_thread::get_id();
+                strm << smt2log << '-' << std::this_thread::get_id();
-                smt2log = symbol(strm.str());                
+                smt2log = symbol(std::move(strm).str());
             }
             to_solver(s)->m_pp = alloc(solver2smt2_pp, mk_c(c)->m(), smt2log.str());
         }
@@ -208,7 +208,7 @@ extern "C" {
         if (!smt_logics::supported_logic(to_symbol(logic))) {
             std::ostringstream strm;
             strm << "logic '" << to_symbol(logic) << "' is not recognized";
-            SET_ERROR_CODE(Z3_INVALID_ARG, strm.str());
+            SET_ERROR_CODE(Z3_INVALID_ARG, std::move(strm).str());
             RETURN_Z3(nullptr);
         }
         else {
@@ -306,7 +306,7 @@ extern "C" {
 
         if (!parse_smt2_commands(*ctx.get(), is)) {
             ctx = nullptr;
-            SET_ERROR_CODE(Z3_PARSER_ERROR, errstrm.str());
+            SET_ERROR_CODE(Z3_PARSER_ERROR, std::move(errstrm).str());
             return;
         }
 
@@ -333,7 +333,7 @@ extern "C" {
         std::stringstream err;
         sat::solver solver(to_solver_ref(s)->get_params(), m.limit());
         if (!parse_dimacs(is, err, solver)) {
-            SET_ERROR_CODE(Z3_PARSER_ERROR, err.str());
+            SET_ERROR_CODE(Z3_PARSER_ERROR, std::move(err).str());
             return;
         }
         sat2goal s2g;
@@ -400,7 +400,7 @@ extern "C" {
         if (!initialized)
             to_solver(s)->m_solver = nullptr;
         descrs.display(buffer);
-        return mk_c(c)->mk_external_string(buffer.str());
+        return mk_c(c)->mk_external_string(std::move(buffer).str());
         Z3_CATCH_RETURN("");
     }
 
@@ -799,7 +799,7 @@ extern "C" {
         init_solver(c, s);
         std::ostringstream buffer;
         to_solver_ref(s)->display(buffer);
-        return mk_c(c)->mk_external_string(buffer.str());
+        return mk_c(c)->mk_external_string(std::move(buffer).str());
         Z3_CATCH_RETURN("");
     }
 
@@ -810,7 +810,7 @@ extern "C" {
         init_solver(c, s);
         std::ostringstream buffer;
         to_solver_ref(s)->display_dimacs(buffer, include_names);
-        return mk_c(c)->mk_external_string(buffer.str());
+        return mk_c(c)->mk_external_string(std::move(buffer).str());
         Z3_CATCH_RETURN("");
     }
 

src/ast/ast_pp.h

@@ -58,13 +58,13 @@ inline std::ostream& operator<<(std::ostream & out, mk_pp_vec const & pp) {
 inline std::string operator+(char const* s, mk_pp const& pp) {
     std::ostringstream strm;
     strm << s << pp;
-    return strm.str();
+    return std::move(strm).str();
 }
 
 inline std::string operator+(std::string const& s, mk_pp const& pp) {
     std::ostringstream strm;
     strm << s << pp;
-    return strm.str();
+    return std::move(strm).str();
 }
 
 inline std::string& operator+=(std::string& s, mk_pp const& pp) {

src/ast/rewriter/pb_rewriter.cpp

@@ -157,9 +157,7 @@ expr_ref pb_rewriter::mk_validate_rewrite(app_ref& e1, app_ref& e2) {
             continue;
         }
 
-        std::ostringstream strm;
+        name = symbol('x' + std::to_string(i));
-        strm << 'x' << i;
-        name = symbol(strm.str());
         trail.push_back(m.mk_const(name, a.mk_int()));
         expr* x = trail.back();
         m.is_not(e,e);
@@ -188,9 +186,7 @@ void pb_rewriter::validate_rewrite(func_decl* f, unsigned sz, expr*const* args,
 }
 
 void pb_rewriter::dump_pb_rewrite(expr* fml) {
-    std::ostringstream strm;
+    std::ofstream out("pb_rewrite_" + std::to_string(s_lemma++) + ".smt2");
-    strm << "pb_rewrite_" << (s_lemma++) << ".smt2";
-    std::ofstream out(strm.str());
     ast_smt_pp pp(m());
     pp.display_smt2(out, fml);    
     out.close();

src/ast/well_sorted.cpp

@@ -70,8 +70,7 @@ struct well_sorted_proc {
                 strm << "Expected sort: " << mk_pp(expected_sort, m_manager) << '\n';
                 strm << "Actual sort:   " << mk_pp(actual_sort, m_manager) << '\n';
                 strm << "Function sort: " << mk_pp(decl, m_manager) << '.';
-                auto str = strm.str();
+                warning_msg("%s", std::move(strm).str().c_str());
-                warning_msg("%s", str.c_str());
                 m_error = true;
                 return;
             }

src/math/lp/numeric_pair.h

@@ -24,7 +24,6 @@
 #include <algorithm>
 #ifdef lp_for_z3
 #include "util/rational.h"
-#include "util/sstream.h"
 #include "util/z3_exception.h"
 #else
 // include "util/numerics/mpq.h"

src/model/model_smt2_pp.cpp

@@ -68,7 +68,7 @@ static void pp_uninterp_sorts(std::ostream & out, ast_printer_context & ctx, mod
             buffer << " ";
         }
         buffer << "\n-----------";
-        std::string buffer_str = buffer.str();
+        std::string buffer_str = std::move(buffer).str();
         unsigned len = static_cast<unsigned>(buffer_str.length());
         pp_indent(out, indent);
         out << ";; ";
@@ -206,9 +206,7 @@ static void pp_funs(std::ostream & out, ast_printer_context & ctx, model_core co
         if (f_i->is_partial()) {
             body = mk_string(m, "#unspecified");
             for (unsigned j = 0; j < f->get_arity(); j++) {
-                std::stringstream strm;
+                var_names.push_back(symbol("x!" + std::to_string(j+1)));
-                strm << "x!" << (j+1);
-                var_names.push_back(symbol(strm.str()));
             }
         }
         else {

src/sat/sat_cutset.cpp

@@ -273,7 +273,7 @@ namespace sat {
     std::string cut::table2string(unsigned num_input, uint64_t table) {
         std::ostringstream strm;
         display_table(strm, num_input, table);
-        return strm.str();
+        return std::move(strm).str();
     }
 
 

src/sat/sat_solver.cpp

@@ -2280,7 +2280,7 @@ namespace sat {
              << std::setw(4) << m_stats.m_restart 
              << mk_stat(*this)
              << " " << std::setw(6) << std::setprecision(2) << m_stopwatch.get_current_seconds() << ")\n";
-        std::string str(strm.str());
+        std::string str = std::move(strm).str();
         svector<size_t> nums;
         for (size_t i = 0; i < str.size(); ++i) {
             while (i < str.size() && str[i] != ' ') ++i;

src/smt/smt_context_pp.cpp

@@ -510,7 +510,7 @@ namespace smt {
 #else
         strm << "lemma_" << (++m_lemma_id) << ".smt2";
 #endif
-        return strm.str();
+        return std::move(strm).str();
     }
 
 
@@ -722,7 +722,7 @@ namespace smt {
              << std::setw(4) << m_stats.m_num_del_clauses << " "
              << std::setw(7) << mem_stat() << ")\n";
 
-        std::string str(strm.str());
+        std::string str = std::move(strm).str();
         svector<size_t> offsets;
         for (size_t i = 0; i < str.size(); ++i) {
             while (i < str.size() && str[i] != ' ') ++i;

src/util/sstream.h

@@ -1,31 +0,0 @@
-/*
-Copyright (c) 2018 Microsoft Corporation
-
-Module Name:
-
-    nat_set.h
-
-Abstract:
-
-    Wrapper for sstream.
-
-Author:
-
-    Leonardo de Moura (leonardo) 2013
-
-Revision History:
-
-*/
-#pragma once
-#include <sstream>
-#include <string>
-
-namespace lean {
-/** \brief Wrapper for std::ostringstream */
-class sstream {
-    std::ostringstream m_strm;
-public:
-    std::string str() const { return m_strm.str(); }
-    template<typename T> sstream & operator<<(T const & t) { m_strm << t; return *this; }
-};
-}

src/util/zstring.cpp

@@ -152,7 +152,7 @@ std::string zstring::encode() const {
         unsigned ch = m_buffer[i];
         if (ch < 32 || ch >= 128 || ('\\' == ch && i + 1 < m_buffer.size() && 'u' == m_buffer[i+1])) {
             _flush();
-            strm << "\\u{" << std::hex << ch << std::dec << "}";
+            strm << "\\u{" << std::hex << ch << std::dec << '}';
         }
         else {
             if (offset == 99)  
@@ -161,7 +161,7 @@ std::string zstring::encode() const {
         }
     }
     _flush();
-    return strm.str();
+    return std::move(strm).str();
 }
 
 bool zstring::suffixof(zstring const& other) const {