Compiler change leads to err?

Code:

---


c_progvs ci_progvs(argc, argv);

    char *p_s_filename_log = &ci_progvs.m_s_filename_log; 
    ofstream f_logfile(p_s_filename_log);

---

The above code worked a while back. I guess my compiler has been upgraded. Still a bit surprised to get:

error : cannot convert 'std::string*' to '*char' in initialisation.

Just would like to know is this a compiler difference? Am I mistaken and my code has been unintentionally changed ?

Fairly sure that previous compiler was MINGW. Now says it is a GNU compiler.

Any help appreciated as I have no technical support to help apart from you guys. Cheers

char *p_s_filename_log = (char*)ci_progvs.m_s_filename_log.c_str();
or:
char *p_s_filename_log = const_cast<char*>(ci_progvs.m_s_filename_log.c_str());

Newest compilers make strong type checking. Your existing code may not work, because it assignes to char* pointer to std::string, this doesn't make sence.

Tx Alex F

I'm afraid I'm making a meal of this. I do not remember having an issue with scope with this code before but .....

Code:

---

if ( y == 0 ) char *p_s_filename_script = const_cast<char*>(ci_progvs.m_s_filename_script1.c_str());

if ( y == 1 ) char *p_s_filename_script = const_cast<char*>(ci_progvs.m_s_filename_script2.c_str());

ifstream scriptfile( p_s_filename_script );

---

And I get an out of scope error. I tried pre-declaring the pointer but to no avail.

Any guidance very welcome cause I'm going round in circles here. Cheers Nigel

1) you should not cast away the const unless there are extreme circumstances.

2) No need to cast away const in this case:

Code:

---

const char * p_s_filename_script;

if (y == 0) p_s_filename_script = ci_progvs.m_s_filename_script1.c_str();
if (y == 1) p_s_filename_script = ci_progvs.m_s_filename_script2.c_str();

ifstream scriptfile( p_s_filename_script );

---

Philip many thanks. I'm now cooking with gas.

I've been looking around for articles on const and casting where I might find some examples. My fat book (Sams Teach Yourself C++) offers a light dusting but no details and examples.

I like using fat books (£30/$50 - 800 pages) if you know what I mean. I find it the simplest way to learn and find them good value. Can anyone suggest an advanced fat book I could use to move on with C++? I need to get to grips with the details. (Note I started 10 months ago and am loving this stuff).

Much appreciate input from you folks here of course. Tx Nigel

Try the 'Effective C++' series by Scott Meyers - I've not read it for a while but he does have some very good stuff in there.

They're not 'FAT' but they are full of content.

Darwen.

Tx Darwen they look the very thing. And I can get access to them online quite cheap to have a good look.

I note there are many 2005 but hopefully you guys here can help me with any recent changes

I've always thought it was a bit odd that the stream classes weren't overloaded to understand std::strings.....