boost::property_tree 没有例外

Question

我需要解析一些 INI 文件。为此，我尝试使用boost::property_tree，但在我的系统中不允许出现异常。

使用boost::property_tree时如何禁用异常支持？

如果没有办法做到这一点，非常感谢任何对其他库的建议。

在@sehe的回答之后，我尝试了这段代码，但没有成功：

#include <iostream>   
#include <string>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/ini_parser.hpp>

namespace boost {
    void throw_exception(std::exception const& e) {
        std::cerr << "Fake exception: " << e.what() << "\n";
        std::exit(255);
    }
}

class Foo {
    public:
      bool bar(const std::string file_name) {
        boost::property_tree::ptree prop_tree;
        boost::property_tree::read_ini(file_name, prop_tree);

        return !prop_tree.empty();
      }
};

编译行代码使用以下参数：

-c -DBOOST_USER_CONFIG="<user.hpp>" -DBOOST_NO_EXCEPTIONS -DBOOST_EXCEPTION_DISABLE -I.\toolchain\boost -I.\include Foo.cpp

最后，user.hpp 文件：

#define BOOST_HAS_NRVO
#define BOOST_NO_COMPLETE_VALUE_INITIALIZATION
#define BOOST_NO_CXX11_AUTO_DECLARATIONS
#define BOOST_NO_CXX11_AUTO_MULTIDECLARATIONS
#define BOOST_NO_CXX11_CHAR16_T
#define BOOST_NO_CXX11_CHAR32_T
#define BOOST_NO_CXX11_CONSTEXPR
#define BOOST_NO_CXX11_DECLTYPE
#define BOOST_NO_CXX11_DECLTYPE_N3276
#define BOOST_NO_CXX11_DEFAULTED_FUNCTIONS
#define BOOST_NO_CXX11_DELETED_FUNCTIONS
#define BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS
#define BOOST_NO_CXX11_FINAL
#define BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS
#define BOOST_NO_CXX11_LAMBDAS
#define BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS
#define BOOST_NO_CXX11_NOEXCEPT
#define BOOST_NO_CXX11_NULLPTR
#define BOOST_NO_CXX11_RANGE_BASED_FOR
#define BOOST_NO_CXX11_RAW_LITERALS
#define BOOST_NO_CXX11_REF_QUALIFIERS
#define BOOST_NO_CXX11_RVALUE_REFERENCES
#define BOOST_NO_CXX11_SCOPED_ENUMS
#define BOOST_NO_CXX11_STATIC_ASSERT
#define BOOST_NO_CXX11_TEMPLATE_ALIASES
#define BOOST_NO_CXX11_UNICODE_LITERALS
#define BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX
#define BOOST_NO_CXX11_USER_DEFINED_LITERALS
#define BOOST_NO_CXX11_VARIADIC_MACROS
#define BOOST_NO_CXX11_VARIADIC_TEMPLATES
#define BOOST_NO_SFINAE_EXPR
#define BOOST_NO_TWO_PHASE_NAME_LOOKUP

编译器返回的一些错误：

"boost/optional/optional.hpp", line 1047: Error:  #312: no suitable user-defined conversion from "boost::bad_optional_access" to "const std::exception" exists
            throw_exception(bad_optional_access());
                            ^

"boost/property_tree/string_path.hpp", line 221: Error:  #312: no suitable user-defined conversion from "boost::property_tree::ptree_bad_path" to "const std::exception" exists
          BOOST_PROPERTY_TREE_THROW(ptree_bad_path("Path syntax error", *this));
          ^

"boost/property_tree/detail/ptree_implementation.hpp", line 78: Error:  #742: namespace "boost" has no actual member "iterator_core_access"
          friend class boost::iterator_core_access;
                              ^

PS：我没有使用广泛可用的标准编译器，但它使用上述相同的过程成功编译了boost::smart_ptr。

Answer 1

您可以将 Boost Exception 配置为不使用异常：

• http://www.boost.org/doc/libs/1_58_0/libs/exception/doc/configuration_macros.html

您需要定义BOOST_NO_EXCEPTIONS 并进一步实现您自己的C 风格异常处理函数，例如

void throw_exception(std::exception const& e) {
    std::cerr << "Fake exception: " << e.what() << "\n";
    std::exit(255);
}

Live On Coliru

#define BOOST_NO_EXCEPTIONS
#include <iostream>
#include <boost/property_tree/ini_parser.hpp>

namespace boost {
    void throw_exception(std::exception const& e) {
        std::cerr << "Fake exception: " << e.what() << "\n";
        std::exit(255);
    }
}

using namespace boost::property_tree;

int main() {
    ptree pt;
    read_ini(std::cin, pt);

    write_ini(std::cout, pt.get_child("section5"));
}

编译

g++ -std=c++11 -O3 -Wall -pedantic main.cpp -fno-exceptions

打印出来

./test <<< "[section1]"
Fake exception: No such node (section5)