This would close issue #41. While the merge key type isn't mentioned in the YAML 1.2 spec, there's a spec for YAML 1.1, and I know I'm not alone in finding it a very useful feature.

Requiring the adoption of the boost libraries so as to use yaml-cpp is 
problematic for many developers.

Given that the C++11 standard library now includes all the features yaml-cpp 
currently uses from boost, it would be good to deprecate the use of boost in 
favour of C++11.

Original issue reported on code.google.com by [email protected] on 12 Nov 2014 at 3:03

Hello!

I have been using yaml-cpp in a project (OpenColorIO), and we just switched 
from svn r423 to r482.   As part of our file format, we often write out a lot 
of 32-bit floats and we noticed that at some point recently yaml-cpp started 
forcing 15 digits of precision on numerical outputs.  (See src/emitter.cpp : 
line 661).   While this makes sense for double values, it's not always 
preferable for float types, as most of the right-most digits will be garbage.

Example: 6.01 -> 6.01000022888184

I'm not sure what the best solutions is, possibilities include:
* using a type-aware precision
* Allowing the user to control the precision explicitly (A new flow control 
type?)

But it would probably make sense to allow for some control of the issue. We're 
using yaml files to allow for 'pretty' output, and this runs counter to that 
philosophy.

Thanks!

Original issue reported on code.google.com by [email protected] on 17 May 2011 at 11:20

Hello,

as per issue title, I'm having a problem when I try to use yaml-cpp in a project I'm working on. Namely, the compiler can't find header files (but I suppose the same will go for libraries) when I try to compile.

This is due to the fact that the file used by CMake to set the paths of include and link directories does not set the proper values for the variables. The content of share/cmake/yaml-cpp/yaml-cpp-config.cmake after installation is;:

# - Config file for the yaml-cpp package
# It defines the following variables
#  YAML_CPP_INCLUDE_DIR - include directory
#  YAML_CPP_LIBRARIES    - libraries to link against

# Compute paths
get_filename_component(YAML_CPP_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
set(YAML_CPP_INCLUDE_DIR "")

# Our library dependencies (contains definitions for IMPORTED targets)
include("${YAML_CPP_CMAKE_DIR}/yaml-cpp-targets.cmake")

# These are IMPORTED targets created by yaml-cpp-targets.cmake
set(YAML_CPP_LIBRARIES "")

As you can see, the variables YAML_INCLUDE_DIR and YAML_CPP_LIBRARIES are empty. I believe the problem may lie in the input file yaml-cpp-config.cmake.in:

# - Config file for the yaml-cpp package
# It defines the following variables
#  YAML_CPP_INCLUDE_DIR - include directory
#  YAML_CPP_LIBRARIES    - libraries to link against

# Compute paths
get_filename_component(YAML_CPP_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
set(YAML_CPP_INCLUDE_DIR "@CONFIG_INCLUDE_DIRS@")

# Our library dependencies (contains definitions for IMPORTED targets)
include("${YAML_CPP_CMAKE_DIR}/yaml-cpp-targets.cmake")

# These are IMPORTED targets created by yaml-cpp-targets.cmake
set(YAML_CPP_LIBRARIES "@EXPORT_TARGETS@")

Indeed, grep-ing for CONFIG_INCLUDE_DIRS or EXPORT_TARGETS yields no results in the whole repository, so substitution should give an empty string.

Am I missing something?

Thanks!

mattia

PR #984 broke the Windows use of the yaml-cpp branch. It was fixed when it was backed out on Sept 28th and it has broken the Windows usage again with the revert of the revert. Here is what happens with the broken submission:

(ClCompile target) -> 
  D:\a\IIS-Module\IIS-Module\yaml-cpp\include\yaml-cpp\parser.h(13,10): fatal error C1083: Cannot open include file: 'yaml-cpp/dll.h': No such file or directory [D:\a\IIS-Module\IIS-Module\main\Native-IIS.vcxproj]
  D:\a\IIS-Module\IIS-Module\yaml-cpp\include\yaml-cpp\parser.h(13,10): fatal error C1083: Cannot open include file: 'yaml-cpp/dll.h': No such file or directory [D:\a\IIS-Module\IIS-Module\main\Native-IIS.vcxproj]
  D:\a\IIS-Module\IIS-Module\yaml-cpp\include\yaml-cpp\parser.h(13,10): fatal error C1083: Cannot open include file: 'yaml-cpp/dll.h': No such file or directory [D:\a\IIS-Module\IIS-Module\main\Native-IIS.vcxproj]
  D:\a\IIS-Module\IIS-Module\yaml-cpp\include\yaml-cpp\parser.h(13,10): fatal error C1083: Cannot open include file: 'yaml-cpp/dll.h': No such file or directory [D:\a\IIS-Module\IIS-Module\main\Native-IIS.vcxproj]

Currently I have yaml-cpp as a git submodule, that gets added using add_subdirectory to my own project. Calling find_package(yaml-cpp) on CMake 3.7 generates the following error:

The file

   .../build/3rdparty/yaml-cpp/yaml-cpp-targets.cmake

  was generated by the export() command.  It may not be used as the argument
  to the include() command.  Use ALIAS targets instead to refer to targets by
  alternative names.

After going through the yaml-cpp CMakeLists.txt I'm not quite sure why this file is needed to be generated. Generating this file through the export command generates the error shown above when being built inside another project (ie. as a submodule).
Note that there's also a SO question here, that has an answer that is not ideal at all for my usage - I want to include it as a submodule and then build it.

Is this really needed? Is there any way I can workaround this problem, besides simply disabling the generation of that file?

What steps will reproduce the problem?
1. compile run-tests

What is the expected output? What do you see instead?
compiled test


What version of the product are you using? On what operating system?
yaml-cpp 0.5.0, VS 2008, Win7

Please provide any additional information below.
The tests do not compile due to missing overloads for some template functions 
for "const char[]" (which is for example called when accessing doc["somekey"] ).

The attached patch fixes this. 

Original issue reported on code.google.com by [email protected] on 10 Jan 2013 at 1:53

Attachments:

• overloads.diff

Per https://cmake.org/cmake/help/latest/policy/CMP0091.html, we need to enable policy CMP0091 if we want to make use of MSVC_RUNTIME_LIBRARY and/or CMAKE_MSVC_RUNTIME_LIBRARY. Fixes issue #912.

The following line https://github.com/jbeder/yaml-cpp/blob/d0da14404ef7cc960ef01bbf97775ead08d3c477/CMakeLists.txt#L325-L330

results in the following error:

CMake Error at 3rdparty/yaml-cpp/CMakeLists.txt:325 (file):
  file RELATIVE_PATH must be passed a full path to the directory:
  install/CMake

every time a cmake file in my project changes. I need to do a complete cache clean for it to be resolved (and then it happens again after I change something). This happens on Windows only and for 2 different projects that I'm aware of.

One option would be to optionally disable yaml-cpp installation, or maybe provide an alternate code path if the path passed to that line is absolute.

Attached is a patch that will correct the CMakeLists.txt for trunk to...
a) correctly create makefiles for shared and static libraries
b) help users that use GCC before 3.4 to get rid of "-Wextra" a little bit 
easier.

I could build DLL and static library via CMake in VS2005 just fine.

Kind regards
Maddes

P.S.:
Yes, I still have to use GCC 3.2 for a project where we want to add YAML 
support.

Original issue reported on code.google.com by [email protected] on 3 Jan 2011 at 8:05

Attachments:

• trunk_cmakelist_lib_fix.patch

This adds yaml-cpp-config.cmake, yaml-cpp-config-version.cmake, and yaml-cpp-targets.cmake to the cmake install. As a result, cmake's find_package can easily find yaml-cpp for software that depends on yaml-cpp.

Closes jbeder/yaml-cpp#336 jbeder/yaml-cpp#127

Undefined symbols for architecture x86_64:
  "YAML::detail::node_data::empty_scalar", referenced from:
      YAML::Node::Scalar() const in config.cc.o
  "YAML::operator<<(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, YAML::Node const&)", referenced from:
      jujimeizuo::Config::LoadFromYaml(YAML::Node const&) in config.cc.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [../lib/libsrc.dylib] Error 1
make[1]: *** [CMakeFiles/src.dir/all] Error 2
make: *** [all] Error 2

when I define std::list<std::pair<std::string, const YAML::Node> >& output, and execute the follow:

output.push_back(std::make_pair(prefix, node));

then the program compile failure, and I get some mistakes as above. But when I Comment out that, I can make successfully.

Loading of block sequence with tag (standard or application) and less than 3 spaces (at the line begin) fails with exception: "end of sequence not found". Such YAML is declared valid with number of online validators.

More details and examples

All following examples are successfully loaded

1. not block sequence

key: !t |
 multiple
 words

2. no tag

key: 
- |
 multiple
 words

3. more than 2 spaces (3)

key: 
- !!str |
   multiple
   words

but the following fail (1 or 2 spaces before "multiple" and "words"):

1. application tag

key: 
- !t |
 multiple
 words

2. standard tag

key: 
- !!str |
  multiple
  words

Possible solution

The change in Scanner::ScanTag:

• remove InsertPotentialSimpleKey(); call

seems to solve this problem, but breaks some of existing tests.

In the tutorial, the example of YAML::convert<> defines a method static bool decode(const Node& node, Vec3& rhs) .

From my understanding, the variable name rhs is commonly used for the right hand side of a binary operator during operator overloading (e.g. for operator/, operator=, operator== etc), which is often (typically unless rvalue ref in operator= (?)) a read-only input argument to the operator.

While "rhs" is a valid variable name, using it for something which is the output of a method is (to me) somewhat confusing. I propose renaming it res or out in all instances of decode, in the tutorial and convert.h.

Setup

File register_info.yaml:

version: "1.0"
organisations:
  - name: "company x"
    registers:
      - name: "register x"
        address: "0x20"
        bitmask: "0x12"
      - name: "register y"
        address: "0x21"
        bitmask: "0xFF"

Code:

  const auto file = "register_info.yaml";
  try {
    const auto yaml = YAML::LoadFile(file);
    const auto& registers = yaml["organisations"][0]["registers"];
    if (registers.IsSequence()) {
      std::cout << "Parsed registers: \n";
      for (const auto& r : registers) {
        const auto ri = r.as<RegisterInfo>();
        std::cout << " - \"" << std::get<const char*>(ri.name) << "\"\n";
      }
    }
  } catch (YAML::Exception& e) {
    std::cerr << e.what() << "\n";
    return EXIT_FAILURE;
  }

Issue

when build with -DCMAKE_BUILD_TYPE=Debug prints:

Parsed registers: 
 - "register x"
 - "register y"

when build with -DCMAKE_BUILD_TYPE=Release prints:

Parsed registers: 
 - ""
 - "register y"

yaml-cpp uses not standard-compliant parsing of a BOM, what makes it unusable with boost::nowide library. See the discussion in this issue.

More concretely, the code in stream.cpp:200 uses multiple calls of std::ifstream::putback(), that is not guaranteed to work with all implementations according to the C++ standard.