*** no comment ***

balance.cc

@@ -85,4 +85,64 @@ void balance_t::write(std::ostream& out,
   }
 }
 
+balance_t& balance_t::operator*=(const balance_t& bal)
+{
+  if (! *this || ! bal) {
+    return (*this = 0L);
+  }
+  else if (amounts.size() == 1 && bal.amounts.size() == 1) {
+    return *this *= (*bal.amounts.begin()).second;
+  }
+  else {
+    std::string msg;
+    std::ostringstream errmsg(msg);
+    errmsg << "It makes no sense to multiply two balances: "
+	   << *this << " * " << bal;
+    throw amount_error(errmsg.str());
+  }
+}
+
+balance_t& balance_t::operator/=(const balance_t& bal)
+{
+  if (! *this) {
+    return (*this = 0L);
+  }
+  else if (! bal) {
+    std::string msg;
+    std::ostringstream errmsg(msg);
+    errmsg << "Attempt to divide by zero: " << *this << " / " << bal;
+    throw amount_error(errmsg.str());
+  }
+  else if (amounts.size() == 1 && bal.amounts.size() == 1) {
+    return *this /= (*bal.amounts.begin()).second;
+  }
+  else if (*this == bal) {
+    return (*this = 1L);
+  }
+  else {
+    std::string msg;
+    std::ostringstream errmsg(msg);
+    errmsg << "It makes no sense to divide two balances: "
+	   << *this << " / " << bal;
+    throw amount_error(errmsg.str());
+  }
+}
+
+balance_t::operator amount_t() const
+{
+  if (amounts.size() == 1) {
+    return (*amounts.begin()).second;
+  }
+  else if (amounts.size() == 0) {
+    return amount_t();
+  }
+  else {
+    std::string msg;
+    std::ostringstream errmsg(msg);
+    errmsg << "Cannot convert a balance with "
+	   << "multiple commodities to an amount: " << *this;
+    throw amount_error(errmsg.str());
+  }
+}
+
 } // namespace ledger

balance.h

@@ -143,11 +143,7 @@ class balance_t
   }
 
   // multiplication and divide
-  balance_t& operator*=(const balance_t& bal) {
+  balance_t& operator*=(const balance_t& bal);
-    if (amounts.size() == 1 && bal.amounts.size() == 1)
-      return *this *= (*bal.amounts.begin()).second;
-    throw amount_error("It makes no sense to multiply two balances");
-  }
   balance_t& operator*=(const amount_t& amt) {
     // Multiplying by the null commodity causes all amounts to be
     // increased by the same factor.
@@ -172,11 +168,7 @@ class balance_t
     return *this *= amount_t(val);
   }
 
-  balance_t& operator/=(const balance_t& bal) {
+  balance_t& operator/=(const balance_t& bal);
-    if (amounts.size() == 1 && bal.amounts.size() == 1)
-      return *this /= (*bal.amounts.begin()).second;
-    throw amount_error("It makes no sense to divide two balances");
-  }
   balance_t& operator/=(const amount_t& amt) {
     // Dividing by the null commodity causes all amounts to be
     // increased by the same factor.
@@ -406,15 +398,7 @@ class balance_t
   }
 
   // conversion operators
-  operator amount_t() const {
+  operator amount_t() const;
-    if (amounts.size() == 1)
-      return (*amounts.begin()).second;
-    else if (amounts.size() == 0)
-      return amount_t();
-    else
-      throw amount_error("Cannot convert a balance with "
-			 "multiple commodities to an amount");
-  }
   operator bool() const {
     for (amounts_map::const_iterator i = amounts.begin();
 	 i != amounts.end();
@@ -427,8 +411,7 @@ class balance_t
   amount_t  amount(const commodity_t& commodity) const;
   balance_t value(const std::time_t moment) const;
 
-  void      write(std::ostream& out,
+  void write(std::ostream& out, const int first_width,
-		  const int	first_width,
 	     const int latter_width = -1) const;
 
   void abs() {

config.cc

@@ -143,6 +143,8 @@ config_t::regexps_to_predicate(const std::string& command,
 	display_predicate += ")/";
       }
       else if (! show_empty) {
+	if (! display_predicate.empty())
+	  display_predicate += "&";
 	display_predicate += "T";
       }
     }