Dear all, I have a problem with Ginac. I'm sorry if my question seems stupid, but I cannot solve the issue. So, I define a new class: class rinterval { public: numeric min; numeric max; numeric error; //Constructor rinterval(); rinterval(const numeric &, const numeric &, const numeric &); //Destructor ~rinterval(); //Friend friend const rinterval dynamic(const rinterval &); friend std::ostream &operator<< (std::ostream &os, const rinterval &inter) { return os << "[" << inter.min << "," << inter.max <<"], error = " << inter.error << endl; }; rinterval& operator=(const rinterval &rhs); }; The involved functions are these rinterval::rinterval(const numeric &input1, const numeric &input2, const numeric &miserr) { if (input1>input2) { min=input2; max=input1; } else { min=input1; max=input2; } error=miserr; } const rinterval dynamic(const rinterval &domain) { numeric a="1.47777777777777777777777777779999"; rinterval temp(a*domain.min,a*domain.max,domain.error); cout << temp; return temp; } rinterval& rinterval::operator=(const rinterval &rhs) { if (this == &rhs) return *this; // Same object? else { try { this->min=rhs.min; this->max=rhs.max; error=rhs.error; } catch(std::exception & exc) { std:cerr << "Exception" << exc.what() << endl; } return *this; } } Now, if inside the main I do int main (void) { numeric a(1,10); numeric b(2,10); rinterval inter(a,b,(numeric)0.00001); inter=dynamic(inter); cout << inter << endl; } I get the following error: *** glibc detected *** ./invmeasure.exe: invalid fastbin entry (free): 0x00000000008ec340 *** ======= Backtrace: ========= /lib/libc.so.6(+0x774b6)[0x7f2c9b11a4b6] /lib/libc.so.6(cfree+0x73)[0x7f2c9b120c83] /usr/lib/libcln.so.6(+0x6fa0d)[0x7f2c9ad91a0d] /usr/lib/libcln.so.6(_ZN3cln11print_floatERSoRKNS_20cl_print_float_flagsERKNS_4cl_FE+0x29)[0x7f2c9ad92d39] /usr/lib/libginac-1.5.so.0(+0x1ddb5b)[0x7f2c9bfbfb5b] /usr/lib/libginac-1.5.so.0(_ZNK5GiNaC7numeric13print_numericERKNS_13print_contextEPKcS5_S5_S5_j+0x97)[0x7f2c9bfc0857] /usr/lib/libginac-1.5.so.0(_ZNK5GiNaC7numeric8do_printERKNS_13print_contextEj+0x28)[0x7f2c9bfc0e48] /usr/lib/libginac-1.5.so.0(_ZNK5GiNaC5basic14print_dispatchERKNS_10class_infoINS_24registered_class_optionsEEERKNS_13print_contextEj+0x18b)[0x7f2c9be6c62b] /usr/lib/libginac-1.5.so.0(_ZN5GiNaClsERSoRKNS_2exE+0x9e)[0x7f2c9bfe5c2e] ./invmeasure.exe[0x404261] ./invmeasure.exe[0x403808] /lib/libc.so.6(__libc_start_main+0xfe)[0x7f2c9b0c1d8e] ./invmeasure.exe[0x403439] ======= Memory map: ======== 00400000-00407000 r-xp 00000000 08:07 66333 /home/isaia/Dropbox/HTGFL/GN-Comput_inv_1D/codice/invmeasure.exe 00607000-00608000 r--p 00007000 08:07 66333 /home/isaia/Dropbox/HTGFL/GN-Comput_inv_1D/codice/invmeasure.exe 00608000-00609000 rw-p 00008000 08:07 66333 /home/isaia/Dropbox/HTGFL/GN-Comput_inv_1D/codice/invmeasure.exe 008c7000-00909000 rw-p 00000000 00:00 0 [heap] 7f2c94000000-7f2c94021000 rw-p 00000000 00:00 0 7f2c94021000-7f2c98000000 ---p 00000000 00:00 0 7f2c9a8be000-7f2c9a91d000 r-xp 00000000 08:07 1523786 /usr/lib/libgmp.so.3.5.2 7f2c9a91d000-7f2c9ab1c000 ---p 0005f000 08:07 1523786 /usr/lib/libgmp.so.3.5.2 7f2c9ab1c000-7f2c9ab1d000 r--p 0005e000 08:07 1523786 /usr/lib/libgmp.so.3.5.2 7f2c9ab1d000-7f2c9ab1e000 rw-p 0005f000 08:07 1523786 /usr/lib/libgmp.so.3.5.2 7f2c9ab1e000-7f2c9ab20000 r-xp 00000000 08:07 262984 /lib/libdl-2.12.1.so 7f2c9ab20000-7f2c9ad20000 ---p 00002000 08:07 262984 /lib/libdl-2.12.1.so 7f2c9ad20000-7f2c9ad21000 r--p 00002000 08:07 262984 /lib/libdl-2.12.1.so 7f2c9ad21000-7f2c9ad22000 rw-p 00003000 08:07 262984 /lib/libdl-2.12.1.so 7f2c9ad22000-7f2c9ae98000 r-xp 00000000 08:07 1549774 /usr/lib/libcln.so.6.0.1 7f2c9ae98000-7f2c9b097000 ---p 00176000 08:07 1549774 /usr/lib/libcln.so.6.0.1 7f2c9b097000-7f2c9b09b000 r--p 00175000 08:07 1549774 /usr/lib/libcln.so.6.0.1 7f2c9b09b000-7f2c9b0a1000 rw-p 00179000 08:07 1549774 /usr/lib/libcln.so.6.0.1 7f2c9b0a1000-7f2c9b0a3000 rw-p 00000000 00:00 0 7f2c9b0a3000-7f2c9b21d000 r-xp 00000000 08:07 262821 /lib/libc-2.12.1.so 7f2c9b21d000-7f2c9b41c000 ---p 0017a000 08:07 262821 /lib/libc-2.12.1.so 7f2c9b41c000-7f2c9b420000 r--p 00179000 08:07 262821 /lib/libc-2.12.1.so 7f2c9b420000-7f2c9b421000 rw-p 0017d000 08:07 262821 /lib/libc-2.12.1.so 7f2c9b421000-7f2c9b426000 rw-p 00000000 00:00 0 7f2c9b426000-7f2c9b43b000 r-xp 00000000 08:07 262222 /lib/libgcc_s.so.1 7f2c9b43b000-7f2c9b63a000 ---p 00015000 08:07 262222 /lib/libgcc_s.so.1 7f2c9b63a000-7f2c9b63b000 r--p 00014000 08:07 262222 /lib/libgcc_s.so.1 7f2c9b63b000-7f2c9b63c000 rw-p 00015000 08:07 262222 /lib/libgcc_s.so.1 7f2c9b63c000-7f2c9b6be000 r-xp 00000000 08:07 262828 /lib/libm-2.12.1.so 7f2c9b6be000-7f2c9b8bd000 ---p 00082000 08:07 262828 /lib/libm-2.12.1.so 7f2c9b8bd000-7f2c9b8be000 r--p 00081000 08:07 262828 /lib/libm-2.12.1.so 7f2c9b8be000-7f2c9b8bf000 rw-p 00082000 08:07 262828 /lib/libm-2.12.1.so 7f2c9b8bf000-7f2c9b9a7000 r-xp 00000000 08:07 1523946 /usr/lib/libstdc++.so.6.0.14 7f2c9b9a7000-7f2c9bba6000 ---p 000e8000 08:07 1523946 /usr/lib/libstdc++.so.6.0.14 7f2c9bba6000-7f2c9bbae000 r--p 000e7000 08:07 1523946 /usr/lib/libstdc++.so.6.0.14 7f2c9bbae000-7f2c9bbb0000 rw-p 000ef000 08:07 1523946 /usr/lib/libstdc++.so.6.0.14 7f2c9bbb0000-7f2c9bbc5000 rw-p 00000000 00:00 0 7f2c9bbc5000-7f2c9bbdd000 r-xp 00000000 08:07 262823 /lib/libpthread-2.12.1.so 7f2c9bbdd000-7f2c9bddc000 ---p 00018000 08:07 262823 /lib/libpthread-2.12.1.so 7f2c9bddc000-7f2c9bddd000 r--p 00017000 08:07 262823 /lib/libpthread-2.12.1.so 7f2c9bddd000-7f2c9bdde000 rw-p 00018000 08:07 262823 /lib/libpthread-2.12.1.so 7f2c9bdde000-7f2c9bde2000 rw-p 00000000 00:00 0 7f2c9bde2000-7f2c9c0c1000 r-xp 00000000 08:07 1524595 /usr/lib/libginac-1.5.so.0.2.0 7f2c9c0c1000-7f2c9c2c0000 ---p 002df000 08:07 1524595 /usr/lib/libginac-1.5.so.0.2.0 7f2c9c2c0000-7f2c9c2cc000 r--p 002de000 08:07 1524595 /usr/lib/libginac-1.5.so.0.2.0 7f2c9c2cc000-7f2c9c2cd000 rw-p 002ea000 08:07 1524595 /usr/lib/libginac-1.5.so.0.2.0 7f2c9c2cd000-7f2c9c2cf000 rw-p 00000000 00:00 0 7f2c9c2cf000-7f2c9c2ef000 r-xp 00000000 08:07 262975 /lib/ld-2.12.1.so 7f2c9c4c3000-7f2c9c4ca000 rw-p 00000000 00:00 0 7f2c9c4ec000-7f2c9c4ef000 rw-p 00000000 00:00 0 7f2c9c4ef000-7f2c9c4f0000 r--p 00020000 08:07 262975 /lib/ld-2.12.1.so 7f2c9c4f0000-7f2c9c4f1000 rw-p 00021000 08:07 262975 /lib/ld-2.12.1.so 7f2c9c4f1000-7f2c9c4f2000 rw-p 00000000 00:00 0 7fff794fd000-7fff7951e000 rw-p 00000000 00:00 0 [stack] 7fff795c7000-7fff795c8000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] I don't understand why, isn't the destruction of the old instances of min and max done by the assignment operator for the type numeric? Thank you in advance Isaia