Error string in namespace std does not name a type

How set std::string type on lldb?

I have the following code:

When i will debug with lldb i want set a std::string like i set this int :

expr std::string $name = «Foo»

error: no type named ‘string’ in namespace ‘std’

Does anyone understand what is going on? How can i create a std::string on lldb ?

Obs:

When i print name , lldb give me this type std::__1::string for std::string :

3 Answers 3

std::string looks simple from the outside but it’s actually a quite complex little beast.

For instance, all the std::string constructors except the copy constructors take defaulted arguments (allocators and the like) that most normal C++ users never override, and so don’t know about. Since we are getting our information about the type from the DWARF debug info, we are restricted by what it represents. It doesn’t represent the values of defaulted arguments, however, so we don’t know how to fill them in.

You can try a little harder by reading the string header, and you figure out you need to provide a size and an allocator, and get to something like:

That fails because the allocator is everywhere inlined, so lldb can’t find a constructor to call for it.

The real solution to this is to have lldb rebuild the std module from headers, import the resultant clang module into lldb’s compiler and use that to create these values. At that point we’d have the information needed to do this job. For instance we would know about defaulted arguments, and could instantiate the missing allocator from the module.

But building a Clang Module from the c++ std headers turns out not to be entirely trivial, so we’re still working on that.

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error: ‘string’ in namespace ‘std’ does not name a type

I have this 2 separated class and i cant fix this compiler problem:

In file included from classA.cpp:2:0: classB.h:6:10: error: ‘string’ in namespace ‘std’ does not name a type std::string str; ^

In file included from classA.cpp:3:0: classA.h:6:25: warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11 classB *ptr_b = new classB;

There is the classA.h:

I apreciate all the help you can give. I don´t know how to fix this and I’m going crazy.

Thanks for reading.

1 Answer 1

You need #include in classB.h . Right now classA.cpp includes classB.h with no prior #include anywhere, so the included reference to std::string in classB.h causes an error.

In general, if a name is used in a header foo.h , you should include the header bar.h that declares the name in foo.h , or forward-declare the name in foo.h . Otherwise everyone else who includes foo.h will need to remember to make sure bar.h gets included first.

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«string is not a type» in namespace

I write a program in c++ with two files.

When I compilered it, It’get wrong.

the wrong infomation is:

In file included from main.cpp:1:0:

var.hpp:9:5: Error： ‘string’ is not a type name

I don’t know why,I had include head file, but it still dosen’t work.

I write this code just for practice, not for work.

3 Answers 3

The problem is the namespace of string in var.hpp . string is the std namespace, but you are not telling the compiler that. You could fix it by putting using namespace std; in var.hpp , but the following is a better solution as it doesn’t clutter the global namespace with other things from std :

You have using namespace std; in your .cpp file, but it comes after the include of var.h . If you’re going to write the header like that, you should put using namespace std; in the header as well.

Alternativly you could use

This avoids having to type std::string in front of every string, and you don’t grab everything from the global namespace.

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Error no type named string in namespace std

HELP! i’m getting what seems like an erroneous error! i’ve got #include in the top of my .cpp, but i keep getting the error ‘string’ does not name a type when i try to compile! why. any ideas? i thought #include was what INCLUDED the library for using strings?? this is in a header file attached to a .cpp that i’m using to store classes and class member functions to be used by the client program, does that make a difference? i’ll throw up the part of my code where it says i have this problem.

please excuse the LIST of includes. my prof told me that if you don’t use it the compiler ignores it so it’s not a bad idea to just make a master list, so you don’t have to keep remembering to type in the ones you need.

Change «string» to «std::string»

Most likely you did not mean to comment out line 12.

Also, what your professor told you only applies when you have optimizations on — in debug mode (no optimizations) it does not apply.

Namespaces were meant to prevent cases where you give something the same name as something in one of those headers. When you write using namespace std you plop all of the stuff in the std namespace into the global namespace so you don’t have to type std:: before everything. It comes at a price: you may accidentally give something the same name as something in the std namespace and cover it up or make it ambiguous as to which you want.

Your fellow students who put std:: before everything have the right idea.

If it is really a hassle you can do things like this:

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string in namespace std does not name a type

Hi guys. I’m aware of the requirement to specify std:: as the namespace for string in some way ( whether it be using namespace std etc) — but the following error has stumped me as to its cause.

This is the only error — and here is a (truncated) Conf.cpp.

Line 33 as shown in the code sample is the definition of the function returning a string.

I’ve tried combinations of using std::string, but each time it states something similar «string does not name a type», «std::string has not been declared» etc..

Any suggestions would be most helpful.

3 Contributors 3 Replies 5K Views 21 Hours Discussion Span Latest Post 13 Years Ago Latest Post by StuXYZ

> #include
This is the old C-style header

#ifndef Conf_H
#include «Conf.h»
#endif
Normally, the header include guards go inside the header file itself.

> #include
This is the old C-style header

#ifndef Conf_H
#include «Conf.h»
#endif
Normally, the header include guards go inside the header file itself.

so I should go back and make all me #include ‘s into #include ?

Using gcc, #include , provides a back-compatability system for stuff like using std::memcpy; etc.

You include that when you are using code that does not use the std::strcpy form but you want to just write strcpy(. ) . Since you almost never want using namespace std; it is a nice half-way house, for importing c like code.

So if you have not included #include , you have only a forward declaration for std::string. Hence the error. [Note that gcc use to include in a lot of other includes, but they have been moving towards a independent #include system, so as you go up the version number you need to be more exact on you #include’s. This means that although your code gets slightly longer your compile time goes down.

So in answer to the question you pose, yes you do need to add #include BUT you may ALSO need #include

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