format_descriptor::format() now yields std::string
This is required since format descriptors for string types that
were using PYBIND11_DESCR were causing problems on C++14 on Linux.
Although this is technically a breaking change, it shouldn't cause
problems since the only use of format strings is passing them to
buffer_info constructor which expects std::string.
Note: for non-structured types, the const char * value is still
accessible via ::value for compatibility purpose.
diff --git a/include/pybind11/common.h b/include/pybind11/common.h
index 9db37ad..eff105c 100644
--- a/include/pybind11/common.h
+++ b/include/pybind11/common.h
@@ -333,14 +333,14 @@
/// Format strings for basic number types
#define PYBIND11_DECL_FMT(t, v) template<> struct format_descriptor<t> \
{ static constexpr const char* value = v; /* for backwards compatibility */ \
- static constexpr const char* format() { return value; } }
+ static std::string format() { return value; } }
template <typename T, typename SFINAE = void> struct format_descriptor { };
template <typename T> struct format_descriptor<T, typename std::enable_if<std::is_integral<T>::value>::type> {
static constexpr const char value[2] =
{ "bBhHiIqQ"[detail::log2(sizeof(T))*2 + (std::is_unsigned<T>::value ? 1 : 0)], '\0' };
- static constexpr const char* format() { return value; }
+ static std::string format() { return value; }
};
template <typename T> constexpr const char format_descriptor<
diff --git a/include/pybind11/numpy.h b/include/pybind11/numpy.h
index c71d9bb..8653fc1 100644
--- a/include/pybind11/numpy.h
+++ b/include/pybind11/numpy.h
@@ -17,6 +17,7 @@
#include <cstdlib>
#include <cstring>
#include <sstream>
+#include <string>
#include <initializer_list>
#if defined(_MSC_VER)
@@ -303,14 +304,14 @@
template <typename T>
struct format_descriptor<T, typename std::enable_if<detail::is_pod_struct<T>::value>::type> {
- static const char *format() { return detail::npy_format_descriptor<T>::format(); }
+ static std::string format() { return detail::npy_format_descriptor<T>::format(); }
};
template <size_t N> struct format_descriptor<char[N]> {
- static const char *format() { PYBIND11_DESCR s = detail::_<N>() + detail::_("s"); return s.text(); }
+ static std::string format() { return std::to_string(N) + "s"; }
};
template <size_t N> struct format_descriptor<std::array<char, N>> {
- static const char *format() { PYBIND11_DESCR s = detail::_<N>() + detail::_("s"); return s.text(); }
+ static std::string format() { return std::to_string(N) + "s"; }
};
NAMESPACE_BEGIN(detail)
@@ -367,11 +368,7 @@
#define DECL_CHAR_FMT \
static PYBIND11_DESCR name() { return _("S") + _<N>(); } \
- static pybind11::dtype dtype() { \
- PYBIND11_DESCR fmt = _("S") + _<N>(); \
- return pybind11::dtype(fmt.text()); \
- } \
- static const char *format() { PYBIND11_DESCR s = _<N>() + _("s"); return s.text(); }
+ static pybind11::dtype dtype() { return std::string("S") + std::to_string(N); }
template <size_t N> struct npy_format_descriptor<char[N]> { DECL_CHAR_FMT };
template <size_t N> struct npy_format_descriptor<std::array<char, N>> { DECL_CHAR_FMT };
#undef DECL_CHAR_FMT
@@ -380,7 +377,7 @@
const char *name;
size_t offset;
size_t size;
- const char *format;
+ std::string format;
dtype descr;
};
@@ -389,15 +386,15 @@
static PYBIND11_DESCR name() { return _("struct"); }
static pybind11::dtype dtype() {
- if (!dtype_())
+ if (!dtype_ptr)
pybind11_fail("NumPy: unsupported buffer format!");
- return object(dtype_(), true);
+ return object(dtype_ptr, true);
}
- static const char* format() {
- if (!dtype_())
+ static std::string format() {
+ if (!dtype_ptr)
pybind11_fail("NumPy: unsupported buffer format!");
- return format_().c_str();
+ return format_str;
}
static void register_dtype(std::initializer_list<field_descriptor> fields) {
@@ -409,7 +406,7 @@
formats.append(field.descr);
offsets.append(int_(field.offset));
}
- dtype_() = pybind11::dtype(names, formats, offsets, sizeof(T)).release().ptr();
+ dtype_ptr = pybind11::dtype(names, formats, offsets, sizeof(T)).release().ptr();
// There is an existing bug in NumPy (as of v1.11): trailing bytes are
// not encoded explicitly into the format string. This will supposedly
@@ -436,20 +433,25 @@
if (sizeof(T) > offset)
oss << (sizeof(T) - offset) << 'x';
oss << '}';
- format_() = oss.str();
+ format_str = oss.str();
// Sanity check: verify that NumPy properly parses our buffer format string
auto& api = npy_api::get();
- auto arr = array(buffer_info(nullptr, sizeof(T), format(), 1, { 0 }, { sizeof(T) }));
- if (!api.PyArray_EquivTypes_(dtype_(), arr.dtype().ptr()))
+ auto arr = array(buffer_info(nullptr, sizeof(T), format(), 1));
+ if (!api.PyArray_EquivTypes_(dtype_ptr, arr.dtype().ptr()))
pybind11_fail("NumPy: invalid buffer descriptor!");
}
private:
- static inline PyObject*& dtype_() { static PyObject *ptr = nullptr; return ptr; }
- static inline std::string& format_() { static std::string s; return s; }
+ static std::string format_str;
+ static PyObject* dtype_ptr;
};
+template <typename T>
+std::string npy_format_descriptor<T, typename std::enable_if<is_pod_struct<T>::value>::type>::format_str;
+template <typename T>
+PyObject* npy_format_descriptor<T, typename std::enable_if<is_pod_struct<T>::value>::type>::dtype_ptr = nullptr;
+
// Extract name, offset and format descriptor for a struct field
#define PYBIND11_FIELD_DESCRIPTOR(Type, Field) \
::pybind11::detail::field_descriptor { \