Generating functions with macros in C++ - c++

I have the following macro that is intended to generate functions in the current scope or namespace:
#define MAKE_FUNC(FNAME) \
template <typename T> \
T ##FNAME## (const T& t) \
{\
return t; \
}
MAKE_FUNC(foo)
MAKE_FUNC(boo)
int main()
{
foo(1);
boo(2);
}
The following is the error message when compiling the above code:
prog.cpp:8:1: error: pasting "Tfoo" and "(" does not give a valid preprocessing token
prog.cpp:9:1: error: pasting "Tboo" and "(" does not give a valid preprocessing token
prog.cpp:8: error: ISO C++ forbids declaration of ‘Tfoo’ with no type
prog.cpp:9: error: ISO C++ forbids declaration of ‘Tboo’ with no type
prog.cpp: In function ‘int main()’:
prog.cpp:13: error: ‘foo’ was not declared in this scope
prog.cpp:14: error: ‘boo’ was not declared in this scope
http://ideone.com/paiu1
It seems like the concatenation has fail, is there anyway around this problem?

You want
T FNAME (const T& t) \
## concatenates, you don't want to concatenate.

Related

What is the meaning of the address symbol & in a constructor?

I'm looking up c++ library, and see the istream class, I am confused with a contractor with an address symbol. what is the meaning of a constructor with an address symbol?
one of the istream constructors is.
protected: iostream& (iostream&& x);
I found it in website cplusplus.com,
link: iostream
I defined a customer class with a similar constructor that has a & symbol:
//Test.cpp
#include <iostream>/*cout,cin*/
#include <typeinfo>/*typeid(),name()*/
using namespace std;
struct MyTest{
MyTest&(double b){}
};
int main(int argc,char* argv[]){
MyTest mt2(2.1);
cout << typeid(mt2).name() << endl;
return 0;
}
I use the below command to compile it:
g++ Test.cpp -o Test -std=c++11
however, I get some compile error messages:
Test.cpp:7:11: error: expected unqualified-id before ‘float’
MyTest&(float b){}
^
Test.cpp:7:11: error: expected ‘)’ before ‘float’
Test.cpp:7:10: error: expected ‘;’ at end of member declaration
MyTest&(float b){}
^
Test.cpp:7:17: error: expected ‘;’ at end of member declaration
MyTest&(float b){}
^
Test.cpp:7:18: error: expected unqualified-id before ‘)’ token
MyTest&(float b){}
^
Test.cpp: In function ‘int main(int, char**)’:
Test.cpp:12:16: error: no matching function for call to ‘MyTest::MyTest(double)’
MyTest mt2(2.1);
I got confused, c++ library istream class is fine. why did my custom class constructor fail? what am I missing?
The information on cplusplus.com is... sometimes not dependable. (See What's wrong with cplusplus.com? for a discussion of this.) On CPPReference, you can see that the move constructor is, you know, just a regular move constructor.
This is a bug in http://www.cplusplus.com/reference/istream/iostream/iostream/.
If you look at https://en.cppreference.com/w/cpp/io/basic_iostream/basic_iostream, you will find
protected: basic_iostream( basic_iostream&& other );

Using Boost Parameter with operator()

I would like to use Boost Parameter together with an overloaded call operator (operator()):
#include <string>
#include <boost/parameter/keyword.hpp>
#include <boost/parameter/preprocessor.hpp>
struct add_argument_tag
{
struct name_;
struct descr_;
};
static inline boost::parameter::keyword<add_argument_tag::name_>& name = boost::parameter::keyword<add_argument_tag::name_>::get();
static inline boost::parameter::keyword<add_argument_tag::descr_>& descr = boost::parameter::keyword<add_argument_tag::descr_>::get();
struct config
{
BOOST_PARAMETER_MEMBER_FUNCTION(
(config),
operator(),
add_argument_tag,
(required (name_, (std::string const&)))
(optional
(descr_, (std::string const&), "")
)
)
{
return *this;
}
};
int main()
{
config my_config;
my_config
("foo")
("bar", descr = "some description");
}
Unfortunately it doesn't work:
In file included from /usr/include/boost/mpl/aux_/integral_wrapper.hpp:22,
from /usr/include/boost/mpl/int.hpp:20,
from /usr/include/boost/mpl/lambda_fwd.hpp:23,
from /usr/include/boost/mpl/aux_/na_spec.hpp:18,
from /usr/include/boost/mpl/identity.hpp:17,
from /usr/include/boost/parameter/aux_/unwrap_cv_reference.hpp:11,
from /usr/include/boost/parameter/keyword.hpp:9,
from /.../main.cpp:2:
/.../main.cpp:18:18: error: expected unqualified-id before ')' token
operator(),
^
/.../main.cpp:18:18: error: expected unqualified-id before ')' token
operator(),
^
/.../main.cpp:18:18: error: expected unqualified-id before ')' token
operator(),
^
/.../main.cpp:16:5: error: expected nested-name-specifier before 'boost_param_result_24operator'
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /.../main.cpp:3:
/.../main.cpp:16:5: error: expected initializer before '<' token
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/boost/mpl/aux_/integral_wrapper.hpp:22,
from /usr/include/boost/mpl/int.hpp:20,
from /usr/include/boost/mpl/lambda_fwd.hpp:23,
from /usr/include/boost/mpl/aux_/na_spec.hpp:18,
from /usr/include/boost/mpl/identity.hpp:17,
from /usr/include/boost/parameter/aux_/unwrap_cv_reference.hpp:11,
from /usr/include/boost/parameter/keyword.hpp:9,
from /.../main.cpp:2:
/.../main.cpp:16:5: error: expected nested-name-specifier before 'boost_param_result_24operator'
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /.../main.cpp:3:
/.../main.cpp:16:5: error: expected initializer before '<' token
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/.../main.cpp:16:5: error: 'boost_param_default_24operator' declared as function returning a function
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/.../main.cpp:16:5: error: 'boost_param_default_24operator' declared as function returning a function
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/boost/mpl/aux_/integral_wrapper.hpp:22,
from /usr/include/boost/mpl/int.hpp:20,
from /usr/include/boost/mpl/lambda_fwd.hpp:23,
from /usr/include/boost/mpl/aux_/na_spec.hpp:18,
from /usr/include/boost/mpl/identity.hpp:17,
from /usr/include/boost/parameter/aux_/unwrap_cv_reference.hpp:11,
from /usr/include/boost/parameter/keyword.hpp:9,
from /.../main.cpp:2:
/.../main.cpp:16:5: error: expected nested-name-specifier before 'boost_param_result_24operator'
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /.../main.cpp:3:
/.../main.cpp:16:5: error: expected initializer before '<' token
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/.../main.cpp:16:5: error: 'boost_param_default_24operator' declared as function returning a function
BOOST_PARAMETER_MEMBER_FUNCTION(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/.../main.cpp: In function 'int main()':
/.../main.cpp:34:15: error: no match for call to '(config) (const char [4])'
("foo")
^
make[3]: *** [CMakeFiles/BoostParameterProblem.dir/build.make:63: CMakeFiles/BoostParameterProblem.dir/main.cpp.o] Error 1
make[2]: *** [CMakeFiles/Makefile2:73: CMakeFiles/BoostParameterProblem.dir/all] Error 2
make[1]: *** [CMakeFiles/Makefile2:85: CMakeFiles/BoostParameterProblem.dir/rule] Error 2
make: *** [Makefile:118: BoostParameterProblem] Error 2
I can easily work around this problem by having a properly named function instead of operator(), but I would really like to use operator() here... :)
I'm guessing the reason is how Boost Parameter uses macros and meta-programming to construct helper functions etc., and that using operator overloading functions are simply not possible.
Is there anyone that have made something like this work? Is it even possible?
Boost Parameter does do a lot of string concatenation stuff, thus your operator() will be concatenated to an invalid name.
One way to workaround is to delegate the operator() to its implementation. Change your macro part to define a normal function, then perfect forwarding all arguments and the final result:
struct config
{
BOOST_PARAMETER_MEMBER_FUNCTION(
(config),
myope,
add_argument_tag,
(required (name_, (std::string const&)))
(optional
(descr_, (std::string const&), "")
)
)
{
std::cout << name_ << " " << descr_ << "\n";
return *this;
}
template<class... Args>
decltype(auto) operator() (Args&& ...args) {
return myope(std::forward<Args>(args)...);
}
};
Live Demo

Error in a ns-3 simulation?

I am trying to run a simulation but I keep getting some kind of error. I am not an expert on C++, but I think it's due to header file include. I am getting the following error:
error: ISO C++ forbids declaration of ‘type name’ with no type [-fpermissive]
void OutInterest(Ptr<const ns3::ndn::InterestHeader> interestHeader,Ptr<const ns3::ndn::Face> face) {
^
../scratch/vndn_simulation.cc:87:52: error: template argument 1 is invalid
void OutInterest(Ptr<const ns3::ndn::InterestHeader> interestHeader,Ptr<const ns3::ndn::Face> face) {
^
../scratch/vndn_simulation.cc:87:28: error: ISO C++ forbids declaration of ‘type name’ with no type [-fpermissive]
void OutInterest(Ptr<const ns3::ndn::InterestHeader> interestHeader,Ptr<const ns3::ndn::Face> face) {
Any idea on how to solve this error?
It says here:
class NameComponents;
^
In file included from ./ns3/ndn-v2v-net-device-face.h:31:0,
from ../scratch/vndn_simulation.cc:15:
./ns3/ndn-header-helper.h:34:21: note: ‘ns3::ndn::NameComponents’ has a previous declaration here
typedef Name NameComponents;
^
that you cannot forward declare NameComponents because the compiler has already seen that it is a typedef and not a class.

CppCMS build constructor & declaration

From http://cppcms.com/wikipp/en/page/cppcms_1x_forms,
According to this,
A declaration introduces one or more names into a program.....
Therefore, classes, structures, enumerated types, and other
user-defined types can be declared for each compilation unit
AFAIK, constructor should be in myapp.cpp, while declaration should be in content.h. So I put
There are 5 fields on the form. In CppCMS, the form built using 3 codes (the 4th codes are restriction for the fields)
1st codes:
name.message("Your Name");
sex.message("Sex");
marital.message("Marital Status");
age.message("Your Age");
submit.value("Send");
2nd codes:
add(name);
add(sex);
add(marital);
add(age);
add(submit);
3rd codes:
sex.add("Male","male");
sex.add("Female","female");
marital.add("Single","single");
marital.add("Married","married");
marital.add("Divorced","divorced");
4th codes, are restriction for the fields:
name.non_empty();
age.range(0,120);
I'm quite confused which one should be declaration
------------------added
I've tried add all above codes in myapp.cpp like below:
class myapp : public cppcms::application {
public:
myapp(cppcms::service &srv) : cppcms::application(srv)
{
dispatcher().assign("",&myapp::info_form,this);
mapper().assign("");
}
void info_form()
{
name.message("Your Name");
sex.message("Sex");
marital.message("Marital Status");
age.message("Your Age");
submit.value("Send");
add(name);
add(sex);
add(marital);
add(age);
add(submit);
sex.add("Male","male");
sex.add("Female","female");
marital.add("Single","single");
marital.add("Married","married");
marital.add("Divorced","divorced");
name.non_empty();
age.range(0,120);
}
};
But it still giving error:
myapp.cpp: In member function ‘void myapp::info_form()’:
myapp.cpp:20:9: error: ‘name’ was not declared in this scope
myapp.cpp:21:9: error: ‘sex’ was not declared in this scope
myapp.cpp:22:9: error: ‘marital’ was not declared in this scope
myapp.cpp:23:9: error: ‘age’ was not declared in this scope
myapp.cpp:24:9: error: ‘submit’ was not declared in this scope
myapp.cpp:24:9: note: suggested alternative:
/usr/local/include/cppcms/form.h:1574:20: note: ‘cppcms::widgets::submit’
myapp.cpp: At global scope:
myapp.cpp:43:37: error: no ‘void myapp::main(std::string)’ member function declared in class ‘myapp’
my_skin.tmpl:4:2: error: expected unqualified-id before ‘if’
my_skin.tmpl:8:3: error: expected unqualified-id before ‘else’
my_skin.tmpl:12:8: error: expected constructor, destructor, or type conversion before ‘<<’ token
my_skin.tmpl:13:2: error: expected unqualified-id before ‘{’ token

GCC 4.1.2 compilation error for stl_vector.h

I am getting the following error for STL files on GCC 4.1.2. And the same code works properly without any compilation errors on GCC 3.4.6.
I am including some built-in headers in my code that in turn include these STL files. Hence, I cannot modify the header files.
I compile it using the following:
gcc -I/grid/0/gs/java/jdk64/current/include -I/grid/0/gs/java/jdk64/current/include/linux -I/grid/0/tmp/direct/include/ydmg/ ydmg.cpp -I/grid/0/tmp/direct/include/ -o libydmg.so
Do I need to include some other parameter while compiling?
Could the compiler version be the cause of this problem?
The error is as follows:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:157: error: expected type-specifier
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:157: error: expected `>'
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:157: error: expected unqualified-id before â>â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:932: error: expected â,â or â...â before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:932: error: âbool ytl::std::operator==(int)â must have an argument of class or enumerated type
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:932: error: âbool ytl::std::operator==(int)â must take exactly two arguments
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: In function âbool ytl::std::operator==(int)â:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:933: error: â__xâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:933: error: â__yâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:934: error: âequalâ is not a member of âytl::stdâ
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: At global scope:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:949: error: expected â,â or â...â before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:949: error: âbool ytl::std::operator<(int)â must have an argument of class or enumerated type
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:949: error: âbool ytl::std::operator<(int)â must take exactly two arguments
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: In function âbool ytl::std::operator<(int)â:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:950: error: âlexicographical_compareâ is not a member of âytl::stdâ
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:950: error: â__xâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:951: error: â__yâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: At global scope:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:956: error: expected â,â or â...â before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:956: error: âbool ytl::std::operator!=(int)â must have an argument of class or enumerated type
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:956: error: âbool ytl::std::operator!=(int)â must take exactly two arguments
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: In function âbool ytl::std::operator!=(int)â:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:957: error: â__xâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:957: error: â__yâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: At global scope:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:962: error: expected â,â or â...â before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:962: error: âbool ytl::std::operator>(int)â must have an argument of class or enumerated type
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:962: error: âbool ytl::std::operator>(int)â must take exactly two arguments
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: In function âbool ytl::std::operator>(int)â:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:963: error: â__yâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:963: error: â__xâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: At global scope:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:968: error: expected â,â or â...â before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:968: error: âbool ytl::std::operator<=(int)â must have an argument of class or enumerated type
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:968: error: âbool ytl::std::operator<=(int)â must take exactly two arguments
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: In function âbool ytl::std::operator<=(int)â:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:969: error: â__yâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:969: error: â__xâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: At global scope:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:974: error: expected â,â or â...â before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:974: error: âbool ytl::std::operator>=(int)â must have an argument of class or enumerated type
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:974: error: âbool ytl::std::operator>=(int)â must take exactly two arguments
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: In function âbool ytl::std::operator>=(int)â:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:975: error: â__xâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:975: error: â__yâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h: At global scope:
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: variable or field âswapâ declared void
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: âytl::std::swapâ declared as an âinlineâ variable
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: template declaration of âint ytl::std::swapâ
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: âvectorâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: expected primary-expression before â,â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: expected primary-expression before â>â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: â__xâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: âvectorâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: expected primary-expression before â,â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: expected primary-expression before â>â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_vector.h:980: error: â__yâ was not declared in this scope
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_bvector.h:110: error: expected template-name before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_bvector.h:110: error: expected `{' before â<â token
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/stl_bvector.h:110: error: expected unqualified-id before â<â token
Any help would be appreciated.
Here is the C++ code.
I am calling the methods from ydmg and yut libraries using JNI.
This code is working perfectly fine on gcc 3.4.6. Its gives errors on gcc 4.1.2.
#include <stdio.h>
#include "ydmg/bd.h"
#include <jni.h>
#include "yut/string.h"
extern "C" int getAge();
JNIEXPORT jint JNICALL Java_ydmgBd_getAge(JNIEnv *, jobject)
{
ydmgBd bdObject;
yutString s = bdObject.getKeys();
printf("\ngetKeys() returns the key as : %s",s.c_str());
yutHash user;
yutString value = "abc";
yutString key ="login";
user.set(key,value);
ydmgBd bd1(user);
bool val = bd1.save(user);
if(val){
printf("\ntrue");
}else {
printf("\nfalse");
}
int age = bd1.getAge();
printf("\nAge : %d ",age);
printf("\nhi");
return 1;
}
int main(){
return 0;
}
If you compile cpp code with gcc and not with g++, you must link with -lstdc++, so that option is definitely missing.
However, the problem already occurs at the parsing step, so my suggestion is to check the namespaces... e.g. have a look at the error output:
...
ytl::std::operator!=
...
std should not be in your personal ytl namespace. You are doing something wrong with your includes.
One of your header files is almost certainly including:
#include <vector>
Before that line, add:
#undef max
And I believe your compiles will start working. This is happening b/c you are also using the C std library, which for some functions uses macros, and in this case, causes the preprocessor to freak out. I've seen this same error on Linux, and undefining that symbol was all i needed to get things compiling again.