Problems using static std::string in shared library

i'm trying to use a C++ library for mechanical simulations in a Qt application. (Project Chrono , Git Hub source).
Everything was ok until i try to use some parts of the library and get some errors. the part of the problematic code is:

ChGlobal.h

//
// PROJECT CHRONO - http://projectchrono.org
//
// Copyright (c) 2010-2011 Alessandro Tasora
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file at the top level of the distribution
// and at http://projectchrono.org/license-chrono.txt.
//

#ifndef CHGLOBAL_H
#define CHGLOBAL_H

#include <string>
#include "core/ChApiCE.h"

namespace chrono {

/// Set the path to the Chrono data directory (ATTENTION: not thread safe)
ChApi void SetChronoDataPath(const std::string& path);

/// Obtain the current path to the Chrono data directory (thread safe)
ChApi const std::string& GetChronoDataPath();

/// Obtain the complete path to the specified filename, given relative to the
/// Chrono data directory (thread safe)
ChApi std::string GetChronoDataFile(const std::string& filename);

}  // END_OF_NAMESPACE____

#endif

ChGlobal.cpp

//
// PROJECT CHRONO - http://projectchrono.org
//
// Copyright (c) 2010 Alessandro Tasora
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file at the top level of the distribution
// and at http://projectchrono.org/license-chrono.txt.
//

#include <string.h>

#include "physics/ChGlobal.h"

#if defined(_WIN32) || defined(_WIN64)
#include "Windows.h"
#endif

#if defined(__APPLE__)
#include <libkern/OSAtomic.h>
#endif

namespace chrono {

// -----------------------------------------------------------------------------
// Functions for manipulating the Chrono data directory
// -----------------------------------------------------------------------------

static std::string chrono_data_path("../data/");

// Set the path to the Chrono data directory (ATTENTION: not thread safe)
void SetChronoDataPath(const std::string& path) {
    chrono_data_path = path;
}

// Obtain the current path to the Chrono data directory (thread safe)
const std::string& GetChronoDataPath() {
    return chrono_data_path;
}

// Obtain the complete path to the specified filename, given relative to the
// Chrono data directory (thread safe)
std::string GetChronoDataFile(const std::string& filename) {
    return chrono_data_path + filename;
}

}  // END_OF_NAMESPACE____

My code in qt is:

const std::string& teste= chrono::GetChronoDataPath();
qDebug()<<"DataPath:"<<teste.c_str();

I get a strange result:

_________
Debugging starts
DataPath: ata/
Debugging has finished
__________

I only get a part of the string.

Then if try to set a new path using the code:

 const std::string& newpath("c:/");
 chrono::SetChronoDataPath(newpath);

i get the follwing error:

Exception at 0x74dfc42d, code: 0xe06d7363: C++ exception, flags=0x1 (execution cannot be continued) (first chance) at f:\dd\vctools\crt\crtw32\heap\new.cpp:62

Is it because of chrono_data_path is a static variable? I've tried another approaches but nothing works. I'm not a C++ expert maybe i'm missing something,

Thanks

The simplest solution is to convert the library and statically link it with your application.

If you insist on dynamically linking the library, you can use the thread-safe Q_GLOBAL_STATIC mechanism:

// implementation (.cpp)

class chrono_data_path_t : public std::string {
public:
  chrono_data_path_t() : std::string("../data/") {}
};

Q_GLOBAL_STATIC(chrono_data_path_t, chrono_data_path)

namespace chrono {

void SetChronoDataPath(const std::string& path) {
    *chrono_data_path = path;
}

const std::string& GetChronoDataPath() {
    return *chrono_data_path;
}

std::string GetChronoDataFile(const std::string& filename) {
    return *chrono_data_path + filename;
}

} // namespace chrono