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Diffstat (limited to 'doc/source/reference/c-api.array.rst')
| -rw-r--r-- | doc/source/reference/c-api.array.rst | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/doc/source/reference/c-api.array.rst b/doc/source/reference/c-api.array.rst index 1291dc93c..b00919fae 100644 --- a/doc/source/reference/c-api.array.rst +++ b/doc/source/reference/c-api.array.rst @@ -3063,6 +3063,24 @@ the C-API is needed then some additional steps must be taken. header file as long as you make sure that NO_IMPORT_ARRAY is #defined before #including that file. + Internally, these #defines work as follows: + + * If neither is defined, the C-API is declared to be + :c:type:`static void**`, so it is only visible within the + compilation unit that #includes numpy/arrayobject.h. + * If :c:macro:`PY_ARRAY_UNIQUE_SYMBOL` is #defined, but + :c:macro:`NO_IMPORT_ARRAY` is not, the C-API is declared to + be :c:type:`void**`, so that it will also be visible to other + compilation units. + * If :c:macro:`NO_IMPORT_ARRAY` is #defined, regardless of + whether :c:macro:`PY_ARRAY_UNIQUE_SYMBOL` is, the C-API is + declared to be :c:type:`extern void**`, so it is expected to + be defined in another compilation unit. + * Whenever :c:macro:`PY_ARRAY_UNIQUE_SYMBOL` is #defined, it + also changes the name of the variable holding the C-API, which + defaults to :c:data:`PyArray_API`, to whatever the macro is + #defined to. + Checking the API Version ^^^^^^^^^^^^^^^^^^^^^^^^ |